determine both the lower and upper limits of a 90% z-confidence interval for µ , the mean score for all students in the school district who are enrolled in gifted and talented programs.

Answers

Answer 1

Answer:

CI = ( μ  -  1,64 * σ /√n ;  μ  +  1,64 * σ /√n )

Step-by-step explanation:

We assume Normal Distribution

For Confidence Interval, CI = 90 %     and  α = 10 %

α = 0,1  and  α/2  =  0,05

So  we will look for z score reciprocate to these values, at the two tails of the bell

z(α/2) = 1,64 at th right tail  and -1,64 at the left

CI = ( μ  ±  1,64 * σ /√n  )

CI = ( μ  -  1,64 * σ /√n ;  μ  +  1,64 * σ /√n )


Related Questions

Why should you find the least common denominator when adding or subtracting rational expressions?

Answers

Answer:

It is necessary to look for the least common denominator when one is trying to add or subtract rational expressions that do not have the same denominator.

Step-by-step explanation:

for example the denominator of the two addends are not the same. One has (x+2), the other (x-2).

karen wants to find the area of the isosceles triangle ABC. she knows that the base of the triangle (side CB) is equal to 8 squares. she also knows the height, or altitude, of the triangle is equal to 4.

Answers

Answer:

16 squares

Step-by-step explanation:

The area of an isosceles is [tex]\frac{bh}{2}[/tex]

[tex]8 \cdot 4 = 32\\32 \div 2 = 16[/tex]

Hope this helped!

Answer:

area = 16 unit ²

Step-by-step explanation:

given:

base = 8

height = 4

req'd : area of a triangle

area of isoceles triangle = 1/2 * b * h

= 1/2 * 8 * 4

= 16 unit²

Geographers use negative numbers to represent points below sea level and positive numbers to represent points above sea level. For example, the lowest point in Minnesota is at -17.3−17.3minus, 17, point, 3 meters, and the highest point is at 14.114.114, point, 1 meters.

What does 000 meters represent?
plzz hurry

Choose 1 answer:

Choose 1 answer:


(Choice A, Checked)

A

The lowest point in Apple Valley


(Choice B)

B

The lowest point in Minnesota


(Choice C)

C

Sea level

Answers

Answer:

C . Sea level

Step-by-step explanation:

If points below the sea level are represented using negative numbers; and

Points above the sea level are represented using positive numbers.

The point labeled 0 meters represents the sea level since it is the indicator of whether a point is positive or negative.

The correct option is C.

Answer:

A)  Sea level

Step-by-step explanation:

Determine all numbers at which are function Continuous..
f(x)={
x^2 + 5x - 36/
x^2 + 8x - 9
if x≠-9
if x= -9}
a.
continuous at every real number except x = 1 and x = -9
b. continuous at every real number except x = -9
c.continuous at every real number except x = 1
d. continuous at every real number except x = -9 and x = 4

Answers

Answer:

For this case we have this function:

[tex] f(x) =\frac{x^2 +5x-36}{x^2 +8x-9}, x=9[/tex]

We can factor the denominator and we got:

[tex] f(x) =\frac{x^2 +5x-36}{(x+9)(x-1)}, x=9[/tex]

And since we can't divide by 0 then the value of x can't be 1 or -9 so then the best answer for this case would be:

Continuous at every real number except x=1 and x=-9

Step-by-step explanation:

For this case we have this function:

[tex] f(x) =\frac{x^2 +5x-36}{x^2 +8x-9}, x=9[/tex]

We can factor the denominator and we got:

[tex] f(x) =\frac{x^2 +5x-36}{(x+9)(x-1)}, x=9[/tex]

And since we can't divide by 0 then the value of x can't be 1 or -9 so then the best answer for this case would be:

Continuous at every real number except x=1 and x=-9

Answer:

A or continuous at every real number except x=1 and x=-9

Step-by-step explanation:

Just took the test :)

Verify by direct substitution that the given power series is a solution of the indicated differential equation. [Hint: For a power x2n + 1 let k = n + 1.] y = (-1) nx2n, (1 + x2)y' + 2xy = 0

Answers

Answer:

The given power series [tex]y =\sum^{\infty}_{n=0} {(-1)^n x^{2n}}[/tex] is a solution of the differential equation (1+x^2)y' + 2xy = 0

Step-by-step explanation:

This is a very trivial exercise, follow the steps below for the solution:

Step 1: Since n = 0, 1, 2, 3, 4, ........, Substitute the values of n into equation (1) below.

[tex]y =\sum^{\infty}_{n=0} {(-1)^n x^{2n}}[/tex].....................(1)

[tex]y = 1 - x^2 + x^4 - x^6 + x^8.........[/tex]

Step 2: Find the derivative of y, i.e. y'

[tex]y' = -2x + 4x^3 - 6x^5 + 8x^7 .............[/tex]

Step 3: Substitute y and y' into equation (2) below:

[tex](1+x^2)y' + 2xy = 0\\\\(1+x^2)(-2x + 4x^3 - 6x^5 + 8x^7......) + 2x(1 - x^2 + x^4 - x^6 + x^8.......) = 0\\\\-2x+ 4x^3 - 6x^5 + 8x^7........ - 2x^3 +4x^5 - 6x^7 + 8x^9 ......+ 2x - 2x^3 + 2x^5 - 2x^7 + 2x^9...... = 0\\\\0 = 0[/tex]

(Verified)

Since the LHS = RHS = 0, the given power series [tex]y =\sum^{\infty}_{n=0} {(-1)^n x^{2n}}[/tex] is a solution of the differential equation (1+x^2)y' + 2xy = 0

x/3 ≥−33 solve for x answer must be simplified

Answers

Answer:

[tex]\boxed{x\geq -99}[/tex]

Step-by-step explanation:

[tex]\frac{x}{3} \geq -33[/tex]

[tex]\sf Multiply \ both \ sides \ by \ 3.[/tex]

[tex]\frac{x}{3} (3) \geq -33(3)[/tex]

[tex]x\geq -99[/tex]

Answer:

[tex]\boxed{\red{x \geqslant - 99}}[/tex]

Step-by-step explanation:

[tex] \frac{x}{3} \geqslant - 33 \\ x \geqslant - 33 \times 3 \\ x \geqslant - 99[/tex]

hope this helps you!

Suppose that there are two types of tickets to a show: advance and same-day. Advance tickets cost 15 and same-day tickets cost 30 . For one performance, there were 55 tickets sold in all, and the total amount paid for them was 1125 . How many tickets of each type were sold?

Answers

Answer:

30 same day 15 advance

Step-by-step explanation:

An anchor lowered at a constant rate into the ocean takes 5 seconds to move -17.5 meters. What is the rate of the anchor in meters per second?

Answers

Answer:

-3.5 meters per second

Step-by-step explanation:

Take the distance and divide by the time

-17.5 meters/ 5 seconds

-3.5 meters per second

Answer:

-3.5 m/s

Step-by-step explanation:

Rate of the anchor =  [tex]\frac{distance}{time}[/tex]

[tex]\frac{-17.5}{5}[/tex]

-3.5 meters per second.

Question 13 of 20 :
Select the best answer for the question.
13. Which of the following groups of numbers are all prime numbers?
O A.2.3,5,9
O B.7.17.29.49
O C.3. 11, 23, 31
O D.2.5, 15, 19
Mark for review (Will be highlighted on the review page)

Answers

Answer: C. 3, 11, 23, 31

Step-by-step explanation:

None of these can be divided by anything except themselves and 1.

Find the area of the trapezoid in the figure below round your final answer to the nearest tenth

Answers

Answer: 60.9 u^2

Step-by-step explanation:

The area of a trapezoid can be calculated as seen in the attachment.

Thus:

[tex]A = \frac{3.7+14.2}{2} * 6.8\\A = \frac{17.9}{2} *6.8\\A = 8.95*6.8\\A = 60.86\\Round\\\left[\begin{array}{c}A=60.9\end{array}\right][/tex]

Hope it helps <3

Answer:

60.9 units^2

Step-by-step explanation:

Well the formula for the area of a trapezoid is,

[tex]\frac{b1+b2}{2} h[/tex]

So b1 and b2 are 142 and 3.7,

14.2 + 3.7 = 17.9

17.9 ÷ 2 = 8.95

8.95 × 6.8 = 60.86

60.9 units^2 rounded to the nearest tenth.

Thus,

the area of the trapezoid is 60.9 units^2.

Hope this helps :)

A car with a standard engine costs $14 000 to purchase and 25€/km to drive. An electric car costs S15 000
to purchase and 20¢/km to operate. How many kilometres would you have to drive for the costs of the
cars to be the same?

Answers

Answer:

200km

Step-by-step explanation:

Car A purchase worth = $14000

Car B purchase worth = $15000

Car A drive worth= 25€ per km

Car B drive worth= 20€ per km

For the worth of the two cars to be equal let's first assume all of the currency to be in dollars$

For A

Worth= 14000+25(x)

For B

Worth= 15000+20(x)

Where x is the distance covered

For the both worth to be equal we equate.

14000+25(x)= 15000+20(x)

25x-20x= 15000-14000

5x= 1000

X= 200

The distance covered by the two cars for the worth to be equal is 200km

6th grade math help me, please :)))

Answers

Answer:

700✖️0.08=56 people is late

700✖️0.12=84 people bought the shirt.

Step-by-step explanation:

8%=0.08

12%=0.12

700✖️0.08=56 people is late

700✖️0.12=84 people bought the shirt.

HOPE THIS HELPS!

A jet flies 425 km from Ottawa to Québec at rate v + 60. On the return flight, the
plane encountered wind resistance and travelled at rate v - 40. What is the
difference in flight times of the initial and return flights?

Answers

Answer:

a. [tex] \frac{- 42,500}{(v + 60)(v - 40)} [/tex]

Step-by-step Explanation:

Given:

Distance Ottawa to Québec = 425 km

Initial flight rate = v + 60

Return flight rate = v - 40

[tex] t = \frac{d}{r} [/tex]

Required:

Flight times difference of the initial and return flights

Solution:

=>Flight time of the initial flight:

[tex] t = \frac{d}{r} [/tex]

[tex] t = \frac{425}{v + 60} [/tex]

=>Flight time of the return flight:

[tex] t = \frac{425}{v - 40} [/tex]

=>Difference in flight times:

[tex] \frac{425}{v + 60} - \frac{425}{v - 40} [/tex]

[tex] \frac{425(v - 40) -425(v + 60)}{(v + 60)(v - 40)} [/tex]

[tex] \frac{425(v) - 425(40) -425(v) -425(+60)}{(v + 60)(v - 40)} [/tex]

[tex] \frac{425v - 17000 -425v - 25500}{(v + 60)(v - 40)} [/tex]

[tex] \frac{425v - 425v - 17000 - 25500}{(v + 60)(v - 40)} [/tex]

[tex] \frac{- 42,500}{(v + 60)(v - 40)} [/tex]

Please help with this

Answers

Answer: B

Step-by-step explanation:

Because of Supplementary Angles, we know that the two angles in the right side of the equation add up to 90.

Hope it helps <3

the endpoints of GH are g(-7,3) and h(1,-2) what’s the midpoint of GH

Answers

Answer:  [tex]\bigg(-3,\dfrac{1}{2}\bigg)[/tex]

Step-by-step explanation:

G = (-7, 3)    H = (1, -2)

[tex]M_{GH}=\bigg(\dfrac{X_G+X_H}{2},\dfrac{Y_G+Y_H}{2}\bigg)\\\\\\.\qquad = \bigg(\dfrac{-7+1}{2},\dfrac{3+(-2)}{2}\bigg)\\\\\\.\qquad = \bigg(\dfrac{-6}{2},\dfrac{1}{2}\bigg)\\\\\\.\qquad = \large\boxed{\bigg(-3,\dfrac{1}{2}\bigg)}[/tex]

The mid point of the line GH whose end points are (-7,3) and (1,-2) is (-3,1/2).

What is the mid point of a line?

The mid point is a line which divides the line into two equal parts. The formula to calculate the mid point of line whose end points are (x1,y1) and (x2,y2) is {(x1+x2)/2,(y1+y2)/2}.

How to calculate mid point of a line?

To calculate the mid point of the line GH we have to put x1=-7, x2=1,y1=3 and y2=-2 so,

the mid point is {(-7+1)/2,(3-2)/2}

=(-3,1/2)

Hence the mid points of a line GH whose end points are g(-7,3) and h(1,-2) is (-3/1/2).

Learn more about mid point of a line at https://brainly.com/question/18315903

#SPJ2

Need Help finding the process for both of these ( due today)

Answers

Similar triangles have side lengths that are proportional to each other. To find each of the missing lengths, we need to set up proportions.

The proportions will look as follows:

(length or unknown of triangle 1) / (length or unknown of triangle 2) = (length of triangle 1) / (length of triangle 2)

-On both sides, remember to be consistent with which length/unknown you put on top! If a triangle 1 length is the numerator on the left, then it also needs to be the numerator on the right! And this also works vice versa with triangle 2.

In each proportion equation, we can only have one unknown. On the left side of the equation, we choose one length or unknown of triangle 1, and the corresponding side length of unknown of triangle 2 (whichever you did not choose from triangle 1). On the right side of the equation, we use a completed proportion. This is because all of the sides of one triangle are proportional to the other triangle, but we need to know that proportion/ratio in order to find other side lengths.

Let's start with problem a, to show how this works:

Triangle 1 side lengths - 16, a, 11

Triangle 2 side lengths - 8, 3, b

As you can tell, the side lengths match up (corresponding!) on each triangle, as in they are in the same position on each triangle. Now, we will set up a proportion to find the length of side a on triangle 1.

a / 3 = 16 / 8

48 = 8a

a = 6

Next, let's find the length of side b on triangle 2.

11 / b = 16 / 8

16b = 88

b = 5.5

Moving on to problem b, we'll apply the same concept and steps from problem a in order to find the missing side lengths.

Triangle 1 side lengths: 5, 5.5, d

Triangle 2 side lengths: 15, c, 18

5 / 15 = 5.5 / c

5c = 82.5

c = 16.5

5 / 15 = d / 18

15d = 90

d = 6

Hope this helps!! :)

Answer:

On a) you can see the shapes are simular. The blue line signatures that they are equal just reduced. You can see that 8 goes into 16 two times so for the orange line 3 must times 2. Which would mean a is 6. Now on the red line all you see is 11. So divide 11 by 2 and your answer should be 5.5 for b.

On b) it is the same thing but you have to find how the blue line is divisible. 5 divided by 15 is 3. So 3 is the number you will be using to divide or multiply. For the orange line you divide 18 by 3. The answer is 6 for d. For the red line 5.5 times 3 and you should get 11 for c.

Step-by-step explanation:

Hope this helped

During the summer months Terry makes and sells necklaces on the beach. Last summer he sold the necklaces for $10 each and his sales averaged 20 per day. When he increased the price by $1, he found that the average decreased by two sales per day. If the material for each necklace costs Terry $6, what should the selling price be to maximize his profit?

Answers

Answer:

The selling price in other to maximize his profit is $13

Step-by-step explanation:

In the above question we are given the following information:

Cost of material per necklace = $6

Firstly, terry sold 20 necklaces per day

= $10 each

Later he increased he increased the prices by 1 dollar and the number of necklaces he sold reduced by 2

Mathematically

18 necklaces = $11 each

Step 1

We find the Cost function C(x)

Let's assume that x = number of necklaces sold

If each material cost $6 , then

C(x) = 6 × x = 6x

Step 2

P(Profit) = R(x) - C(x)

R(x) = Revenue

Where Revenue = x × p(x)

Since p(20) = 10 and p(18) = 11

p(x) = -1/2x + 20

P(Profit) = x ( -1/2x + 20) - C(x)

C(x) = 6x

P = x(-1/2x + 20) - 6x

P = -1/2x² + 20x - 6x

P = -1/2x² + 14x

Step 3

We maximise the profit by differentiating P

P = Profit

P = -1/2x² + 14x

We differentiate P to find x

∆P/∆x = dp/dx = -x + 14

-x + 14 = 0

-x = -14

x = 14

Hence, we substitute 14 for x in the price function

p(x) = - 1/2x + 20

since , x = 14

p(14) = - 1/2 × 14 + 20

= -7 + 20

= $13

Therefore, the selling price function to maximize his profit is $13

Above question the given data:  

Cost of material per necklace = $6 Terry sold 20 necklaces per day = $10 each Price increase by 1 dollar Number of necklaces  sold reduced by 2  

1.Cost function C(x)

Let's assume that x = number of necklaces sold

If each material cost $6 , then

C(x) = 6 × x

C(x) = 6x  

2.P(Profit) = R(x) - C(x)

R(x) = Revenue ,Where Revenue = x × p(x)

Given data:

p(20) = 10

p(18) = 11

p(x) = -1/2x + 20

P(Profit) = R(x) - C(x)

P(Profit) = x ( -1/2x + 20) - C(x)

P = x(-1/2x + 20) - 6x

P = -1/2x² + 20x - 6x

P = -1/2x² + 14x

 

3.Maximise Profit

P = Profit  

P = -1/2x² + 14x

We differentiate P to find x

∆P/∆x = dp/dx = -x + 14

-x + 14 = 0

-x = -14

x = 14

Now, we will substitute 14 for x in the price function

Now ,p(x) = - 1/2x + 20

since , x = 14

p(14) = - 1/2 × 14 + 20  

p(14)= -7 + 20  

p(14)= $13

Thus, the selling price function to maximize his profit is $13.

Learn more :

https://brainly.com/question/24710158?referrer=searchResults

if f(x) = √(x²-9) , then Domain of f = __________ (a) (-∞,-3)∪(3,∞) (b) (-∞,-3]∪ [3,∞) (c) (-∞,∞) (d) [-3,3]

Answers

Answer:

domain is:(-∞,-3]∪ [3,∞)

Step-by-step explanation:

f(x)=√(x²-9)

f(x)=√(x-3)(x+3)

domain is:(-∞,-3]∪ [3,∞)

x(x+3)(x+3)=0 Please I NEED HELP FAST! PLLLLLLLLLLLLLLLLLLLLLLLLLLEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEAAAAAAAAAAAAAAAAAAAAAAAAAAAAASSSSSSSSSSSSSSSSSSSSSSSSSSEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!

Answers

Answer:

[tex]\boxed{x^3+6x^2+9x}[/tex]

Step-by-step explanation:

[tex]x(x+3)(x+3)[/tex]

Resolving the first parenthesis

[tex](x^2+3x) (x+3)[/tex]

Using FOIL

[tex]x^3+3x^2+3x^2+9x[/tex]

Adding like terms

[tex]x^3+6x^2+9x[/tex]

[tex]\text{If } \: a\cdot b \cdot c = 0 \text{ then } a=0 \text{ or } b =0 \text{ or } c=0 \text{ or all of them are equal to zero.}[/tex]

[tex]x(x+3)(x+3) =0[/tex]

[tex]\boxed{x_1 =0}[/tex]

[tex]x_2+3 =0[/tex]

[tex]\boxed{x_2 = -3}[/tex]

[tex]x_3+3 =0[/tex]

[tex]\boxed{x_3 = -3}[/tex]

Belen wants to create a nut-mix. She can buy peanuts for $1.80 per pound and cashews for $4.50 per pound. If she wants to make a 10 pounds of nut-mix at a cost of $2.61 per pound, how many pounds of peanuts and how many pounds of cashews should she buy?

Answers

Answer:

7 and 3 respectively

Step-by-step explanation:

Peanuts (p/lb) = $1.80

Cashews (p/lb) = $4.50

Total pound = 10 pounds

Aggregate amount (at $2.61 per lb) = $26.1

Pound of peanut to buy = x

Pound of cashew to buy = y

x + y = 10..........(i)

1.8x + 4.5y = 26.1.....(ii)

Multiply equ (i) by 1.8 and equ (ii) by 1

1.8x + 1.8y = 18

1.8x + 4.5y = 26.1

Subtract (i) from (ii)

4.5y - 1.8y = 26.1 - 18

2.7y = 8.1

y = 3

Sub y = 3 into (i)

x + y = 10

x + 3 = 10

x = 10 - 3

= 7

Pounds of peanut to buy = 7 pounds

Pounds of cashew to buy = 3 pounds

Enter the correct answer in the box by replacing the values of a and b. f(x) = a(b)^x

Answers

Answer:

f(x)= 8(0.5)^x

Step-by-step explanation:

As you can see on the graph there are two specific points labeled:

(0,8) and (1,4)

The 8 would be the initial value and starting point of the "design"

A is always the initial value so replace that.

Then proceed to divide 4 by 8 to figure out the percentage change its 0.5

leave x as it is

A scale diagram of a garden shows the length as 14.5cm. If the scale is 1:150, what is the actual length? The garden is _______m in length.

Answers

Answer:

21.75m

Step-by-step explanation:

14.5×150 =2175cm

1m =100cm

to convert into m divide 2175 by 100

=21.75m

which of the following graph represents the solution set for the inequality 3 - 1/2 x > 10

Answers

Answer:

56

Step-by-step explanation:

Find the balance in Asturos savings account if he deposits $2100 at 3.5% simple interest for 2 years

Answers

Answer:

2250

Step-by-step explanation:

Balance : 2100

2 Years

2100 ÷ 100 x 103.5 ÷ 100 x 103.5 = 2249.5725

I really need help on this question

Answers

Answer:

d. 38

Step-by-step explanation:

AB = AD - BD = 54 - 36 = 18

AC = AB + BC = 18 + 20 = 38

A movie earned $438 million at the box office in
2013. That is 24% more than book of the same
name earned. Estimate how much the book
earned?
Round your answer to the nearest hundredth of
a million dollars.

Answers

Answer:

332.88 million

Step-by-step explanation:

you do the thing

331.36 is the answer.
You can take 76% of 438 to find the answer

Suppose you deposit $600 into an account that pays 5% annual interest, compounded continuously. How much will you have in the account in 4 years? ƒ(t) = aert A) $4,433.43 B)635.62 C)$729.30 D)$732.84

Answers

Answer:

D)$732.84

Step-by-step explanation:

A=p(1+r/n)^nt

P=principal=$600

r=5%=0.05

t=4 years

n=12 months

A=p(1+r/n)^nt

=600(1+0.05/12)^12*4

=600(1+0.0041666666666 )^48

=600(1.0041666666666 )^48

=600( 1.2208953550215 )

=732.53

A=$732.53

Option D)$732.84 is the answer

PLEASE HELP QUICK!!! A bowl has 85 pieces of candy. Nineteen children empty the bowl of candy. Some children take 3 pieces, some children take 5 pieces, and 1 child takes 7 pieces of candy. How many children take 3 pieces of candy?

Answers

Answer: 3 kids take 3 pieces of candy each

Step-by-step explanation:

Let the number of children that took 3 pieces is x ( total take 3*x pieces of candy)

Number of children that took 5 pieces is y ( total take 5*y pieces of candy)

1 child took 1 piece that actually means that x+y=18 and 3*x+5*y=84.

( Because total number of all kids is 19. We just deduct one kid (Let his name is John) who took only 1 candy.  So we have 19-1 =18 kids without John. The similar is with the candies. Total number is 85. We deduct 1 piece which John has taken. )

So we have 2 equations or the system of 2 equations:

1).  x+y=18

2). 3*x +5*y=84

Multuply both sides of equation 1) by 3

We have   3*x+3*y=18*3

Deduct 3*y from both sides of this equation

3*x+3*y-3*y=54-3*y

3*x=54-3*y

Substitute 3*x in equation  2).  by 54-3*y

2) 54-3*y+5*y=84

2*y=30

y=15  ( kids take 5 pieces of candy each)

Using equation 1) find x

x+15=18

x=3 (kids take 3 pieces of candy each)

Evaluate 7(-4) - |-6| + |4| a 13 b -18 c -30

Answers

Answer:

C. -30

Step-by-step explanation:

We would have to do order of operations or P.E.M.D.A.S. So fist we would do 7 times -4 which is -28 than we would do the absolute value of -6 which is 6 so we would do -28-6 which is -34 and we would do the absolute value of 4 which is 4 and we would add it to -34 which is -30 so our final answer would be C. -30

assume that when adults with smartphones are randomly selected 42 use them in meetings or classes if 15 adult smartphones are randomly selected, find the probability that "fewer" than 4 of them use their smartphones

Answers

Complete Question

Assume that when adults with smartphones are randomly selected 42% use them in meetings or classes if 15 adult smartphones are randomly selected, find the probability that "fewer" than 4 of them use their smartphones

Answer:

The  probability is  [tex]P[X < 4]= 0.00314[/tex]

Step-by-step explanation:

From the question we are told that

      The proportion of those that use smartphone in meeting and classes is  p = 0.42

     The sample size is  [tex]n = 15[/tex]

   The proportion of those that don't use  smartphone in meeting and classes is  

          [tex]q = 1- p[/tex]

=>        [tex]q = 1- 0.42[/tex]

=>         [tex]q = 0.58[/tex]

Now  from the question we can deduce that the usage of the smartphone is having a  binomial  distribution since there is only two outcome  

So  the probability that "fewer" than 4 of them use their smartphones is mathematically evaluated as

       [tex]P[X < 4 ] = P[X = 0] + P[X = 1] +P[X = 2] +P[X = 3][/tex]=

=>     [tex]P[X < 4] = [ \left 15} \atop {0}} \right. ] p^{15-0} * q^0 + [ \left 15} \atop {1}} \right. ] p^{15-1 }* q^1 + [ \left 15} \atop {2}} \right. ] p^{15-2 }* q^2 + [ \left 15} \atop {3}} \right. ] p^{15-3 }* q^3[/tex]

Where  [tex][\left 15} \atop {0}} \right. ][/tex] implies 15  combination 0 which has a value of  1 this is obtained using a scientific calculator

  So for the rest of the equation we will be making use of a scientific calculator to obtain the combinations

      [tex]P[X < 4] = 1 * ^{15} * q^0 + 15 * p^{14 }* q^1 + 105 * p^{13 }* q^2 + 455 * p^{12 }* q^3[/tex]

substituting values

       [tex]= 1 * (0.42)^{15} * (0.58)^0 + 15 * (0.42)^{14 }* (0.58)^1[/tex]

                     [tex]+ 105 * (0.42)^{13 }* (0.58)^2 + 455 * (0.42)^{12 }* (0.58)^3[/tex]

=>       [tex]P[X < 4]= 0.00314[/tex]

Other Questions
Solve for x Your answer must be simplified. 2x These are the poems Poem 1: Fire and Ice by Robert Frost Poem 2: This Is Just to Say by William Carlos Williams 1st paragraph: talk about the similarities of both authors 2nd paragraph: talk about the differences between both authors I need a good and full response for the paragraphs :) A formal hypothesis test is to be conducted using the claim that the mean AC thermostat setting in restaurants is equal to 74degreesF. What is the null hypothesis and how is it denoted? In the end, how did Napoleon Bonaparte make use of the Louisiana Territory?A. He established a successful trade partnership with the Indians.B. He used it as a base to fight Spanish colonies in South America.C. He sold it in order to help pay for a war with Great Britain.D. He established a colony in partnership with the United States. PLEASE HELPP!! What change in worldview did many of those living through the Great Depression experience? A. Hopelessness and a desire to look out for oneself B. Frugality and a sense of local unity C. Renewal of religion and the rise of local churches D. Hard work and a feeling of individualism During the first month of operations ended July 31, YoSan Inc. manufactured 2,400 flat panel televisions, of which 2,000 were sold. Operating data for the month are summarized as follows: Sales $2,150,000 Manufacturing costs: Direct materials $960,000 Direct labor 420,000 Variable manufacturing cost 156,000 Fixed manufacturing cost 288,000 1,824,000 Selling and administrative expenses: Variable $204,000 Fixed 96,000 300,000 Required: 1. Prepare an income statement based on the absorption costing concept. YoSan Inc. Absorption Costing Income Statement For the Month Ended July 31 $ Cost of goods sold: $ $ $ 2. Prepare an income statement based on the variable costing concept. YoSan Inc. Variable Costing Income Statement For the Month Ended July 31, 2016 $ Variable cost of goods sold: $ $ $ Fixed costs: $ $ 3. Explain the reason for the difference in the amount of income from operations reported in (1) and (2). The income from operations reported under costing exceeds the income from operations reported under costing by the difference between the two, due to manufacturing costs that are deferred to a future month under costing. The students are studying for an exam in pharmacology. They know several local anesthetics have been covered along with other forms. Which medication can they anticipate as being local anethetics on the exam? a) marcaine b) xylocaine c) novocain The administration of Midwest State University wants to know if the arrangement of chairs affects student participation in classrooms. What would be a good operational definition of the dependent variable in an experiment designed to measure this relationship 7 (42 3) + 4 (72 + 53) + 8 (-3) 4 Why was it important for Europeans to find a direct trade route to Asia? European traders wanted to see the famed wealth and power of Asia's empires. Arabic and Venetian traders controlled the overland routes and the prices of goods. Advances in ships and navigational technology made a direct route possible. Safe passage into the Mongol Empire simplified trading for Europeans. Think about the boy you saw in this section of the video. Sort his behaviors as a speaker by how effective they are.using more text evidenceHow the Speaker Was Effective How the Speaker Could Improvereading before the discussionconnecting to others' viewssupporting his opinions If your good in math pls help me Im not that great and Im ineed of help ! Bethesda Water has an issue of preferred stock outstanding with a coupon rate of 4.30 percent that sells for $91.18 per share. If the par value is $100, what is the cost of the company's preferred stock As Devine rides her bike, she picks up a nail in her front tire. The height, h, of the nail from the ground as she rides her bike over time, t, in seconds, is modelled by the equation below: As Devine rides her bike, she picks up a nail in her front tire. The height, h, of the nail from the ground as she rides her bike over time, t, in seconds, is modelled by the equation below:f(x)=-14 cos(720(t-10))+14 Using the equation, determine the following. Show your work for part marks. a) What is the diameter of the bike wheel? b) How long does it take the tire to rotate 3 times? c) What is the minimum height of the nail? Does this height make sense? Why? Please answer this question now Poulter Corporation will pay a dividend of $4.60 per share next year. The company pledges to increase its dividend by 6.75 percent per year, indefinitely. If you require a return of 11 percent on your investment, how much will you pay for the companys stock today? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) (6/7)^2 times (1/2)^2 Aracely can spend up to a total of $20 on streamersand balloons for a party. Streamers cost $1.49 perpack, and balloons cost $4.39 per pack. Which ofthe following inequalities represents this situation,where is the number of packs of streamers Aracelycan buy, and b is the number of pack of balloonsAracely can buy? (Assume there is no sales tax.) Break-Even Sales and Sales to Realize Income from Operations For the current year ended October 31, Friedman Company expects fixed costs of $361,200, a unit variable cost of $43, and a unit selling price of $64. a. Compute the anticipated break-even sales (units). units b. Compute the sales (units) required to realize income from operations of $84,000. units On a CVP chart, on either side of the break-even point, the vertical distance between the total sales line and the total cost line represents: