Answer:
-3x-12
Step-by-step explanation:
-10x-4-8+7x
-3x-4-8
-3x-12
Answer:
-3x-12
Step-by-step explanation:
– 10x + – 4 – 8 + 7x
Combine like terms
-10x +7x -4-8
-3x -12
need help thanksssss
Before we can find any of the three items mentioned, we need the height. The diameter is 10, so the radius is 5. A right triangle with hypotenuse 13 and leg 5 forms. The height is h. Use the pythaogrean theorem to solve for h
5^2+h^2 = 13^2
25+h^2 = 169
h^2 = 169-25
h^2 = 144
h = sqrt(144)
h = 12
The height is 12. We now have enough info to find the volume, the lateral area and surface area.
-------------------------------------------------------------------
Volume
V = (1/3)*pi*r^2*h
V = (1/3)*3.14*5^2*12
V = 314 cubic cm
-------------------------------------------------------------------
Lateral Area
LA = pi*r*L
LA = 3.14*5*13
LA = 204.1 square cm
-------------------------------------------------------------------
Surface Area
SA = 2*pi*r + pi*r*L .... note how we add on the lateral area to the bottom circular area
SA = 2*3.14*5 + 3.14*5*13
SA = 235.5 square cm
Change -4Y - 3X = -8 to the slope-intercept form of the equation of a line.
Answer:
y=-3/4x+2
Step-by-step explanation:
Add +3x both sides.
Divide each side by -4
-8/-4=2
Slope = -3/4
Y-intercept= 2
Probability equation need help again. worded problem-the table below displays the number of siblings for students. at one school. Find the probability that a randomly selected students has 2 siblings.
what is the length of a hypotenuse of a triangle if each of its legs is 4 units
Answer:
[tex]\boxed{c = 5.7 units}[/tex]
Step-by-step explanation:
Using Pythagorean Theorem:
=> [tex]c^2 = a^2+b^2[/tex]
Where c is hypotenuse, a is base and b is perpendicular and ( a, b = 4)
=> [tex]c^2 = 4^2+4^2[/tex]
=> [tex]c^2 = 16+16[/tex]
=> [tex]c^2 = 32[/tex]
Taking sqrt on both sides
=> c = 5.7 units
Answer:
5.65 unitsStep-by-step explanation:
Given,
Base ( b ) = 4 units
Perpendicular ( p ) = 4 units
Hypotenuse ( h ) = ?
Now,
Using Pythagoras theorem to find length of hypotenuse:
[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]
Plugging the values
[tex] {h}^{2} = {4}^{2} + {4}^{2} [/tex]
Evaluate the power
[tex] {h}^{2} = 16 + 16[/tex]
Calculate the sum
[tex] {h}^{2} = 32[/tex]
[tex]h = \sqrt{32} [/tex]
[tex]h = 5.65 \: units[/tex]
Hope this helps..
Best regards !!
Pick two cards at random from a well-shuffled deck of 52 cards (pick them simultaneously so they are not the same card). There are 12 cards considered face cards. There are 4 cards with the value 10. Let X be the number of face cards in your hand. Let Y be the number of 10's in your hand. Explain why X and Y are dependent.
Answer:
The variables X and Y are dependent.
Step-by-step explanation:
The variable X denotes number of face cards . That is it can take values,
X = {0, 1, 2 }
Compute the probability for all he values of X as follows:
P [X = 0] = P (None of the 12 card is chosen in either draw)
= (40/52)×(39/51)
= 1560/2652
= 0.5882
P [X = 1] = P (One of the card is face card is selected)
= 2×(40/52)×(12/51)
= 960/2652
= 0.3619
P [X = 2] = P (Two of the 12 card is chosen in the draw)
= (12/52)×(11/51)
= 132/2652
= 0.0498
The variable Y denotes number of cards numbered 10 . Thus, it can take values:
Y = {0, 1, 2 }
P [Y = 0] = P (None of the 4 card is chosen in either draw)
= (48/52)×(47/51)
= 2256/2652
= 0.8507
P [Y = 1] = P (One of the 4 card is chosen in either draw)
= 2×(4/52)×(48/51)
= 384/2652
= 0.1448
P [Y = 2] = P (Two of the 4 card is chosen in the draw)
= (4/52)×(3/51)
= 12/2652
= 0.0045
Now compute the probability of (X and Y).
P [X = 0 and Y = 0] = P(None of the 16 card is chosen in either draw)
= (36/52)×(35/51)
= 1260/2652
= 0.4751
The variables X and Y are independent if,
P [X = 0 and Y = 0] = P [X = 0] × P [Y = 0]
= P [X = 0] × P [Y = 0]
= 0.8507 × 0.5882
= 0.5204
The two values are not equal.
Hence, the variables X and Y are not independent.
Find X.
Round to the nearest tenth.
Law of Cosines : c2 = 22 + b2 - 2ab cos C
Answer:
70.5°
Step-by-step explanation:
22² = (20)²+(18)² - 2(20)(18) cos X
484 = 400 + 324 - 720 cos X
-240 = -720 cosx
1/3 = cos X
[tex]cos^{-1}(\frac{1}{3})[/tex] = X
X = 70.52877937
A train travels 45 feet in 1/10 if a second. How far will it travel in 3.5 seconds
Answer:
1575 ft
Step-by-step explanation:
Convert 1/10 to decimal to make the math simpler.
1/10 = 0.1
Divide 3.5 by 0.1.
3.5/0.1 = 35
Multiply 35 by 45.
35 × 45 = 1575
The train will travel 1575 feet in 3.5 seconds.
The distance covered by the train in 3.5 seconds will be 1575 feet.
What is speed?The distance covered by the particle or the body in an hour is called speed. It is a scalar quantity. It is the ratio of distance to time.
We know that the speed formula
Speed = Distance/Time
A train travels 45 feet in 1/10 in a second.
Then the speed will be
Speed = 45 / (1/10)
Speed = 45 x 10
Speed = 450 feet per second
The distance covered by the train in 3.5 seconds will be
Distance = 450 x 3.5
Distance = 1575 feet
More about the speed link is given below.
https://brainly.com/question/7359669
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A basketball coach is curious about the heights of players in the league. Let the proportion of basketball players who are over 72 inches be p. If the coach wanted to know if the proportion of basketball players who are over 72 inches is more than 85%, what are the null and alternative hypothesis? Select the correct answer below: H0: p=0.85; Ha: p<0.85 H0: p>0.85; Ha: p=0.85 H0: p=0.85; Ha: p>0.85 H0: μ=0.85; Ha: μ>0.85
Answer:
H0: p=0.85;
Ha: p>0.85
Step-by-step explanation:
What was being tested is that:
the coach wanted to know if the proportion of basketball players who are over 72 inches is more than 85%.
The null hypothesis which we are testing against would be that the proportion of basketball players who are over 72 inches is 85%.
H0: p=0.85;
Ha: p>0.85
i will give brainliest and 50 points pls help ASAP
Answer:
answer is 2.3 hope you get the answer
Edit: I figured it out, it's 14+7(sqrt sign) 2
A square piece of paper is folded once so that one pair of opposite corners coincide. When the paper is unfolded, two congruent triangles have been formed. Given that the area of the original square is $49$ square inches, what is the number of inches in the perimeter of one of these triangles? Express your answer in simplest radical form.
Answer:
[tex]Perimeter = 14 + 7\sqrt{2}[/tex]
Step-by-step explanation:
Given:
Area of the square = 49 in²
Required
Determine the perimeter of the one of the congruent triangles
First, we'll determine the length of the square;
[tex]Area = Length * Length[/tex]
Substitute 49 for Area
[tex]49 = Length * Length[/tex]
[tex]49 = Length^2[/tex]
Take Square root of both sides
[tex]7 = Length[/tex]
[tex]Length = 7[/tex]
When the square is divided into two equal triangles through the diameter;
2 sides of the square remains and the diagonal of the square forms the hypotenuse of the triangle;
Calculating the diagonal, we have;
[tex]Hypotenuse^2 = Length^2 + Length^2[/tex] -- Pythagoras Theorem
[tex]Hypotenuse^2 = 7^2 + 7^2[/tex]
[tex]Hypotenuse^2 = 2(7^2)[/tex]
Take square root of both sides
[tex]Hypotenuse = \sqrt{2} * \sqrt{7^2}[/tex]
[tex]Hypotenuse = \sqrt{2} * 7[/tex]
[tex]Hypotenuse = 7\sqrt{2}[/tex]
The perimeter of one of the triangles is the sum of the 2 Lengths and the Hypotenuse
[tex]Perimeter = Length + Length + Hypotenuse[/tex]
[tex]Perimeter = 7 + 7 + 7\sqrt{2}[/tex]
[tex]Perimeter = 14 + 7\sqrt{2}[/tex]
All sides of the building shown above meet at right angles. If three of the sides measure 2 meters, 7 meters, and 11 meters as shown, then what is the perimeter of the building in meters?
Answer:
69 meters
Step-by-step explanation:
Answer:
Please privately chat to us why you chose to cheat during online class, otherwise we will contact your parents and kick you out of our program for the reason stated.
Step-by-step explanation:
Please contact your Quantitive Reasoning teacher at her email, as stated in Google Classroom.
Translate into an algebraic expression and simplify if possible. The value of a number whose units digit is x and whose tens digit is three more than the units digit.
Answer: 11x + 30
Step-by-step explanation: Algebraic expression is a way of use letters to express relationships between algarisms.
For this question:
Units digit = x
Tens digit = 10(x + 3)
The number in question is:
10(x + 3) + x
10x + 30 + x
To simplify, add, subtract, multipy or divide similar terms:
As x is of the first order:
10x + x + 30
11x + 30
The simplified algebraic expression is 11x + 30
I NEED THE ANSWER AS SOON AS POSSIBLE PLEASE!!
Answer:
[tex]\Large \boxed{\sf \ \ 4\sqrt{a^2+b^2} \ \ }[/tex]
Step-by-step explanation:
Hello,
You can use Pythagoras in the 4 right triangles.
For one triangle it comes [tex]\sqrt{a^2+b^2}[/tex].
Then for the polygon it gives [tex]4\cdot \sqrt{a^2+b^2}[/tex].
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
A Cepheid variable star is a star whose brightness alternately increases and decreases. For a certain star, the interval between times of maximum brightness is 5.7 days. The average brightness of this star is 5.0 and its brightness changes by ±0.25. In view of these data, the brightness of the star at time t, where t is measured in days, has been modeled by the function B(t) = 5.0 + 0.25 sin 2πt 5.7 .Find the rate of change of the brightness after t days.
Correct expression of B(t) is;
B(t) = 5.0 + 0.25 sin(2πt/5.7)
Answer:
B'(t) = (5π/57)cos(2πt/5.7)
Step-by-step explanation:
We are given;
B(t) = 5.0 + 0.25 sin(2πt/5.7)
Now the rate of change of the brightness after t days is simply the derivative of B(t)
Thus;
B'(t) = 0 + [{0.25 cos(2πt/5.7)} × (2π/5.7)]
This leads to;
B'(t) = (0.5π/5.7)cos (2πt/5.7)
Simplifying this further gives;
B'(t) = (5π/57)cos(2πt/5.7)
subtract 2-3/4-1 1/10=
Answer:
23/20
Step by step Explanation
Answer:
3/20Step-by-step explanation:
[tex]2-\frac{3}{4}-1\frac{1}{10}=x\\x=2-\frac{3}{4}-\frac{11}{10}\\\mathrm{Convert\:element\:to\:fraction}:\quad \:2=\frac{2}{1}\\x=\frac{2}{1}-\frac{3}{4}-\frac{11}{10}\\1,\:4,\:10\\\mathrm{Prime\:factorization\:of\:} ;\\1=1\\4=2\times \:2\\10=2\cdot \:5\\\mathrm{Multiply\:the\:numbers:}\:2\times \:2\times \:5=20\\Adjust\: fractions\: based\: on\: their\: LCM ;\\\frac{2}{1}=\frac{2\times \:20}{1\times \:20}=\frac{40}{20}\\\\\frac{3}{4}=\frac{3\times \:5}{4\times \:5}=\frac{15}{20}\\[/tex]
[tex]\frac{11}{10}=\frac{11\times \:2}{10\times \:2}=\frac{22}{20}\\\mathrm{Since\:the\:denominators\:are\:equal,\\\:combine\:the\:fractions}:\\\quad \frac{a}{c}\pm \frac{b}{c}=\frac{a\pm \:b}{c}\\\\\mathrm{Subtract\:the\:numbers:}\:40-15-22=3\\\\x=\frac{3}{20}[/tex]
Please! help and tell me the answers, or help me figure out these answers for 20 points? please! And please help me. Can anybody help me?
Answer:
1. Pattern (rule) : y = x-6
2. Pattern (rule) : y=x^2+1
3. Pattern (rule) : y = -3x
4. Pattern (rule) : y = 2x-2
5. Pattern (rule) : y = x^2
Step-by-step explanation:
Note: question number correspond to your order of questions.
1. Pattern (rule) : y = x-6
for missing parts, see attached table.
2. Pattern (rule) : y=x^2+1
3. Pattern (rule) : y = -3x
4. Pattern (rule) : y = 2x-2
5. Pattern (rule) : y = x^2
Suppose you just flipped a fair coin 8 times in a row and you got heads each time! What is the probability that the next coin flip will result in a heads
Answer:
The probability is 1
Step-by-step explanation:
Given
Number of flips = 8
Outcomes = 8 heads
Required
Probability of getting a head in the next row
This problem can be attributed to experimental probability and it'll be solved using experimental probability formula, which goes as follows;
[tex]Probability = \frac{Number\ of\ Occurence}{Total\ Trials}[/tex]
Let [tex]P(Head)[/tex] represents the probability of getting a head in the next row;
[tex]P(Head)= \frac{Outcome\ of\ head}{Total\ Flips}[/tex]
[tex]P(Head)= \frac{8}{8}[/tex]
[tex]P(Head)= 1[/tex]
Hence, the probability of obtaining a head in the next flip is 1
Find the distance between the points (–9, 0) and (2, 5). Find the distance between the points (–9, 0) and (2, 5).
Answer:
sqrt( 146)
Step-by-step explanation:
To find the distance, we use the following formula
d = sqrt( ( x2-x1) ^2 + ( y2-y1) ^2)
sqrt( ( -9-2) ^2 + ( 0-5) ^2)
sqrt( ( -11) ^2 + ( -5) ^2)
sqrt( 121+25)
sqrt( 146)
The diameter of ball bearings produced in a manufacturing process can be explained using a uniform distribution over the interval 3.5 to 4.75 millimeters. What is the probability that a randomly selected ball bearing has a diameter greater than 4.4 millimeters?
Answer:
The probability is 0.28
Step-by-step explanation:
Here, we want to calculate the probability that the ball bearing randomly selected has a diameter greater then 4.4 mm
I.e P(X> 4.4)
P(X>4.4) = (4.75-4.4)/(4.75-3.5) = 0.35/1.25 = 0.28
A random sample of 64 students at a university showed an average age of 20 years and a sample standard deviation of 4 years. The 90% confidence interval for the true average age of all students in the university is
Answer:
The 90% confidence level is [tex]19.15< L < 20.85[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n = 64[/tex]
The mean age is [tex]\= x = 20 \ years[/tex]
The standard deviation is [tex]\sigma = 4 \ years[/tex]
Generally the degree of freedom for this data set is mathematically represented as
[tex]df = n - 1[/tex]
substituting values
[tex]df = 64 - 1[/tex]
[tex]df = 63[/tex]
Given that the level of confidence is 90% the significance level is mathematically evaluated as
[tex]\alpha = 100 - 90[/tex]
[tex]\alpha =[/tex]10 %
[tex]\alpha = 0.10[/tex]
Now [tex]\frac{\alpha }{2} = \frac{0.10}{2} = 0.05[/tex]
Since we are considering a on tail experiment
The critical value for half of this significance level at the calculated degree of freedom is obtained from the critical value table as
[tex]t_{df, \frac{ \alpha}{2} } = t_{63, 0.05 } = 1.669[/tex]
The margin for error is mathematically represented as
[tex]MOE = t_{df , \frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }[/tex]
substituting values
[tex]MOE = 1.699 * \frac{4 }{\sqrt{64} }[/tex]
[tex]MOE = 0.85[/tex]
he 90% confidence interval for the true average age of all students in the university is evaluated as follows
[tex]\= x - MOE < L < \= x + E[/tex]
substituting values
[tex]20 - 0. 85 < L < 20 + 0.85[/tex]
[tex]19.15< L < 20.85[/tex]
Which of the following inequalities is not true?
A) -2/2 < 3
B) |-1| ≥ 0
C) |-9| ≠ |9|
D) -7 ≤ -5
Answer:
C) |-9| != |9|
Step-by-step explanation:
The definition of absolute value is simply the non-negative value of the argument without regards to the sign. With this in mind, let's walk through these options.
A) -2/2 < 3 ==> -1 < 3 which is True
B) |-1| >= 0 ==> 1 >= 0 which is True since 1 is > 0
C) |-9| != |9| ==> 9 != 9 which is False since 9 == 9
D) -7 <= -5 which is True since -7 is < -5
Cheers
Solve 2x2 – 6x + 10 = 0 by completing the square.
Answer: x = 6.32 or -0.32
Step-by-step explanation:
2x² - 6x + 10 = 0
No we divide the expression by 2 to make the coefficient of x² equals 1
We now have
x² - 3x + 5 = 0
Now we remove 5 to the other side of the equation
x² - 3x = -5
we add to both side square of half the coefficient of x which is 3
x² - 3x + ( ⁻³/₂)² = -5 + (⁻³/₂)²
(x - ³/₂)² = -5 + ⁹/₄
Resolve into fraction
(x - ³/₂)² = ⁻¹¹/4
Take the roots of the equation
x - ³/₂ = √¹¹/₄
x - ³/₂ = √11/₂
x = ³/₂ ± 3.32/₂
= 3+ 3.32 or 3 - 3.32
= 6.32 or - 0.32
In the figure below, which term best describes point L?
Explanation:
The tickmarks show which pieces are congruent to one another, which in turn show the segments have been bisected (cut in half). The square angle markers show we have perpendicular segments. So we have three perpendicular bisectors. The perpendicular bisectors intersect at the circumcenter. The circumcenter is the center of the circumcircle. This circle goes through all three vertex points of the triangle.
A useful application is let's say you had 2 friends and you three wanted to pick a location to meet for lunch. Each person traveling from their house to the circumcenter's location will have each person travel the same distance. We say the circumcenter is equidistant from each vertex point of the triangle. In terms of the diagram, LH = LJ = LK.
Answer: B.) Circumcenter
Step-by-step explanation:
The diagram shows a right triangle and three squares. The area of the largest square is 55 units.
Which could be the areas of the smaller squares?
Choose all answers that apply:
A
12 and 43
B
14 and 40
16 and 37
Answer:
It's 12 and 43
Step-by-step explanation:
A square is a plane shape with equal length of sides, while a right triangle is a triangle that has one of its angles to be [tex]90^{o}[/tex]. Thus, the areas of the smaller squares could be:
A. 12 and 43
A square has equal length of sides, so that its area is given as:
Area of a square = length x length
= [tex]l^{2}[/tex]
For the largest square its area = 55 [tex]units^{2}[/tex], so that:
Area = [tex]l^{2}[/tex]
⇒ 55 = [tex]l^{2}[/tex]
l = [tex]\sqrt{55}[/tex]
Now applying the Pythagoras theorem to the right triangle, we have:
[tex]/Hyp/^{2}[/tex] = [tex]/Adj 1/^{2}[/tex] + [tex]/Adj 2/^{2}[/tex]
where hypotenuse = [tex]\sqrt{55}[/tex]
([tex]\sqrt{55}[/tex][tex])^{2}[/tex] = [tex]/Adj 1/^{2}[/tex] + [tex]/Adj 2/^{2}[/tex]
[tex]/Adj 1/^{2}[/tex] + [tex]/Adj 2/^{2}[/tex] = 55
Therefore, the addition of the areas of the smaller squares should be equal to that of the largest square.
Thus from the theorem above, the areas of the smaller squares could be 12 and 43.
i.e 12 + 43 = 55
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The random variable x is the number of houses sold by a realtor in a single month at the Sendsom's Real Estate office. Its probability distribution is as follows:
Houses Sold (x) Probability P(x)
0 0.24
1 0.01
2 0.12
3 0.16
4 0.01
5 0.14
6 0.11
7 0.21
Find the mean of the given probability distribution.
A. μ = 3.35
B. μ = 3.50
C. μ = 3.60
D. μ = 3.40
Answer:
C. μ = 3.60
Step-by-step explanation:
Two tables have been attached to this response.
One of the tables contains the given data and distribution with two columns: Houses Sold and Probability
The other table contains the analysis of the data with additional columns: Frequency and Fx
=> The Frequency(F) column is derived from the product of the probability of each item in the Houses sold column and the total number of houses sold (which is 28). For example,
When the number of houses sold = 0
F = P(0) x Total number of houses sold
F = 0.24 x 28 = 6.72
When the number of houses sold = 1
F = P(1) x Total number of houses sold
F = 0.01 x 28 = 0.28
=> The Fx column is found by multiplying the Frequency column by the Houses Sold column. For example,
When the number of houses sold = 0
Fx = F * x
F = 6.72 x 0 = 0
Now to get the mean, μ we use the relation;
μ = ∑Fx / ∑F
Where;
∑Fx = summation of the items in the Fx column = 100.8
∑F = summation of the items in the Frequency column = 28
μ = 100.8 / 28
μ = 3.60
Therefore, the mean of the given probability distribution is 3.60
The mean of the discrete probability distribution is given by:
C. μ = 3.60
What is the mean of a discrete distribution?The expected value of a discrete distribution is given by the sum of each outcome multiplied by it's respective probability.
In this problem, the table x - P(x) gives each outcome and their respective probabilities, hence, the mean is:
[tex]E(X) = 0(0.24) + 1(0.01) + 2(0.12) + 3(0.16) + 4(0.01) + 5(0.14) + 6(0.11) + 7(0.21) = 3.6[/tex]
Hence option C is correct.
More can be learned about the mean of discrete distributions at https://brainly.com/question/24855677
There are 45 balloons: 15 are blue; 20 are green; 10 are red. 3 balloons are selected for the float. Leaving your answers in combinatorics format, how many ways can all 3 be selected such that they are the same color.
Answer: Required number of ways = 1715
Step-by-step explanation:
Given, there are 45 balloons: 15 are blue; 20 are green; 10 are red.
3 balloons are selected for the float.
Number of combinations to select r things out of n things : [tex]^nC_r=\dfrac{n!}{r!(n-r)!}[/tex]
So, the number of ways to select 3 ballons such that they are the same color = (Ways to select all blue ) x (Ways to select all green ) x (Ways to select all red)
[tex]^{15}C_3+^{20}C_3+^{10}C_3\\\\=\dfrac{15!}{12!\times3!}+\dfrac{20!}{17!\times3!}+\dfrac{10!}{7!\times3!}\\\\=\dfrac{15\times14\times13}{6}+\dfrac{20\times19\times18}{6}+\dfrac{10\times9\times8}{6}\\\\=455+1140+120\\\\=1715[/tex]
Hence, Required number of ways = 1715
Please help. I’ll mark you as brainliest if correct! Don’t understand this math problem.
Answer:
work is pictured and shown
Answer:
Infinitely many solutions.
Step-by-step explanation:
To solve the system of equation using the substitution method, the problem has already given us a solution for x:
x = -4y - 9
Using this, we can plug that into the first equation and solve for y:
3x + 12y = -27
3(-4y - 9) + 12y = -27
-12y - 27 + 12y = -27
-27 = -27
The fact that our solution indicate -27 = -27 means that these two equations have infinitely many solutions for the value y. This simply means that no matter what we put in for y, the statement will always be true.
Notice that these two equations are in fact the same equation:
x = -4y - 9 ==> x + 4y = -9 ==> 3x + 12y = -27
Since these two equations are the same, then there are infinitely many solutions.
I'm not sure quite what they want for the form in terms of y, but let's solve for y since they already solved for x:
x = -4y - 9
x + 9 = -4y
y = (-1 / 4) (x + 9)
Cheers.
please I need help with this question!
The weight of adult males in Boston are normally distributed with mean 69 kilograms and variance 25 kilograms.
I. what percentage of adult male in Boston weigh more than 72 kilograms?
ii. what must an adult male weigh in order to be among the heaviest 10% of the population?
Thank you in advance!
Answer:
lmkjhvjgcfnhjkhbmgnc gfghh
Step-by-step explanation:
Need help with graphing
Fifty students are enrolled in a Business Statistics class. After the first examination, a random sample of 5 papers was selected. The grades were 60, 75, 80, 70, and 90. a) Determine the standard error of the mean
Answer:
The standard error S.E of the mean is 5
Step-by-step explanation:
From the given data;
Fifty students are enrolled in a Business Statistics class.
After he first examination, a random sample of 5 papers was selected.
Now; let consider a random sample of 5 papers was selected. with the following grades : 60, 75, 80, 70, and 90
The objective of this question is to determine the standard error of the mean
In order to achieve this ; we need to find the mean and the standard deviation from the given data.
TO start with the mean;
Mean [tex]\overline X[/tex] = [tex]\dfrac{1}{n} \sum x_i[/tex]
Mean [tex]\overline X[/tex] = [tex]\dfrac{1}{5} (60+75+80+70+90)[/tex]
Mean [tex]\overline X[/tex] = 0.2(375)
Mean [tex]\overline X[/tex] = 75
On the other hand; the standard deviation is :
[tex]s = \sqrt{\dfrac{1}{n-1}\sum(x_i - \overline X)^2}[/tex]
[tex]s = \sqrt{\dfrac{1}{5-1}((60-75)^2+(75-75)^2+(80-75)^2+(70-75)^2+(90-75)^2 )}[/tex]
[tex]s = \sqrt{\dfrac{1}{4}(225+0+25+25+225 )}[/tex]
[tex]s = \sqrt{\dfrac{1}{4}(500 )}[/tex]
[tex]s = \sqrt{125}[/tex]
s = 11.18
Finally; the standard error S.E of the mean is:
[tex]S.E = \dfrac{s}{\sqrt{n}}[/tex]
[tex]S.E = \dfrac{11.18}{\sqrt{5}}[/tex]
[tex]S.E = \dfrac{11.18}{2.236}[/tex]
[tex]S.E = 5[/tex]
The standard error S.E of the mean is 5