Answer:
The confidence interval is [tex]-11.34 < \mu_1 -\mu_2 < -10.86[/tex]
Step-by-step explanation:
From the question we are told that
The first sample size is [tex]n_1 = 146[/tex]
The second sample size is [tex]n_2 = 180[/tex]
The first sample mean is [tex]\= x_1 = 51.6[/tex]
The second sample mean is [tex]\= x_2 = 62.7[/tex]
The first standard deviation is [tex]\sigma _1 = 9.42[/tex]
The second standard deviation is [tex]\sigma _2 = 14.5[/tex]
Given that the confidence level is 98% then the significance level is mathematically evaluated as
[tex]\alpha = (100 -98 )\%[/tex]
[tex]\alpha = 2 \%[/tex]
[tex]\alpha = 0.02[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the z-table , the value is [tex]Z_{\frac{\alpha }{2} } = 2.33[/tex]
The reason we are obtaining critical value of
[tex]\frac{\alpha }{2}[/tex]
instead of
[tex]\alpha[/tex]
is because
[tex]\alpha[/tex]
represents the area under the normal curve where the confidence level interval (
[tex]1-\alpha[/tex]
) did not cover which include both the left and right tail while
[tex]\frac{\alpha }{2}[/tex]
is just the area of one tail which what we required to calculate the margin of error
NOTE: We can also obtain the value using critical value calculator (math dot armstrong dot edu)
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \sqrt{ \frac{\sigma_1^2}{n_1^2} + \frac{\sigma_2^2}{n_2^2} }[/tex]
substituting values
[tex]E = 2.33 * \sqrt{ \frac{9.42^2}{146^2} + \frac{14.5^2}{180^2} }[/tex]
substituting values
[tex]E = 2.33 * \sqrt{ \frac{9.42^2}{146^2} + \frac{14.5^2}{180^2} }[/tex]
[tex]E = 0.2405[/tex]
The 98% confidence interval is mathematically represented as
[tex](\= x _ 1 - \= x_2 ) - E < \mu_1 -\mu_2 < (\= x _ 1 - \= x_2 ) + E[/tex]
substituting values
[tex](51.6 - 62.7) - 0.2405 < \mu_1 -\mu_2 < (51.6 - 62.7) + 0.2405[/tex]
[tex]-11.34 < \mu_1 -\mu_2 < -10.86[/tex]
Find the equation, in standard form, of the line passing through the points
(2,-3) and (4,2).
Answer:
Standard form = y = mx + c
m = Δy/Δx
m = 5/2
y = 5/2 x + c
Sub in (4,2)
2 = 10 + c
c = -8
y = 5/2 x - 8
Step-by-step explanation:
verify sin4x - sin2x = cos4x-cos2x
Answer:
sin⁴x - sin²x = cos⁴x - cos²x
Solve the right hand side of the equation
That's
sin⁴x - sin²x
From trigonometric identities
sin²x = 1 - cos²xSo we have
sin⁴x - ( 1 - cos²x)
sin⁴x - 1 + cos²x
sin⁴x = ( sin²x)(sin²x)
That is
( sin²x)(sin²x)
So we have
( 1 - cos²x)(1 - cos²x) - 1 + cos²x
Expand
1 - cos²x - cos²x + cos⁴x - 1 + cos²x
1 - 2cos²x + cos⁴x - 1 + cos²x
Group like terms
That's
cos⁴x - 2cos²x + cos²x + 1 - 1
Simplify
We have the final answer as
cos⁴x - cos²xSo we have
cos⁴x - cos²x = cos⁴x - cos²xSince the right hand side is equal to the left hand side the identity is true
Hope this helps you
-s^2+2s=0 Separate the two values with a comma.
Answer:
s = 0 OR s = 2
Step-by-step explanation:
=> [tex]-s^2+2s = 0[/tex]
=> [tex]-s(s-2)=0[/tex]
So, Either:
=> -s = 0 OR s-2 = 0
=> s = 0 OR s = 2
Answer:
s=0,2
Step-by-step explanation:
-s^2+2s=0
Factor out -s
-s ( s-2) =0
Using the zero product property
-s =0 s-2 =0
s=0 s=2
Which of the hypothesis tests listed below is a left-tailed test? Select all correct answers. Select all that apply: H0:μ=18, Ha:μ<18 H0:μ=19.3, Ha:μ>19.3 H0:μ=8, Ha:μ≠8 H0:μ=11.3, Ha:μ<11.3 H0:μ=3.7, Ha:μ<3.7
Answer:
H0:μ=18, Ha:μ<18
H0:μ=11.3, Ha:μ<11.3
H0:μ=3.7, Ha:μ<3.7
Step-by-step explanation:
A left tailed test is a type of test usually taken from the alternative hypothesis that includes only one of either the less than or greater than options and not both.
A left tailed test corresponds with the less than option and in this case study, the left tailed test are:
H0:μ=18, Ha:μ<18
H0:μ=11.3, Ha:μ<11.3
H0:μ=3.7, Ha:μ<3.7
A newsgroup is interested in constructing a 95% confidence interval for the proportion of all Americans who are in favor of a new Green initiative. Of the 556 randomly selected Americans surveyed, 421 were in favor of the initiative. Round answers to 4 decimal places where possible.
Required:
a. With 99% confidence the proportion of all Americans who favor the new Green initiative is between ______ and______ .
b. If many groups of 593 randomly selected Americans were surveyed, then a different confidence interval would be produced from each group. About ________percent of these confidence intervals will contain the true population proportion of Americans who favor the Green initiative and about _______? percent will not contain the true population proportion.
Answer:
(A) With 99% confidence, the proportion that favours the Green initiative is between 418.895 and 423.105 (no approximation; answers were gotten exactly in 3 decimal places).
(B) If many groups of 593 (greater than the initial sample size of 556) randomly selected Americans were surveyed then a different confidence interval would be used or produced from each group.
About 90% of these confidence intervals will contain the true population proportion of Americans who favour the Green initiative and about 10% will not contain the true population proportion.
Step-by-step explanation:
(A) 99% of 421 = 416.79
421 - 416.79 = 4.21
4.21 ÷ 2 = 2.105
(421-2.105), (421+2.105)
The lower and upper limits are:
[418.895 , 423.105]
(B) A wider confidence interval such as 90% will be better suited in a case of multiple samples like this.
In △ABC,a=11 , b=20 , and c=28 . Find m∠A .
Answer:
18.4°
Step-by-step explanation:
Use law of cosine.
a² = b² + c² − 2bc cos A
11² = 20² + 28² − 2(20)(28) cos A
121 = 1184 − 1120 cos A
cos A = 0.949
A = 18.4°
Nearsightedness: It is believed that nearsightedness affects about 8% of all children. In a random sample of 194 children, 21 are nearsighted.
(a) What proportion of children in this sample are nearsighted?
(b) Construct hypotheses appropriate for the following question: do these data provide evidence that the 8% value is inaccurate?
(c) Given that the standard error of the sample proportion is 0.0195 and the point estimate follows a nearly normal distribution, calculate the test statistic (the Z statistic).
(d) What is the p-value for this hypothesis test?
(e) What is the conclusion of the hypothesis test?
Answer:
a)the proportion of student is 0.1082
b)
H1: p = .08
H2: p not equal to 0.08
H1: p =0 .08
H2: p < .08
H1: p =0 .08
H2: p >0 .08
c)z=1.45
d) the p value is 0.1470
e)null hypothesis cannot be accepted,There is no enough evidence to reject the null hypothesis.
Step-by-step explanation:
CHECK THE ATTACHMENT FOR DETAILED EXPLANATION
a study of the annual population of toads in a county park shows the population, S(t), can be represented by the function S(t) = 152(1.045)^t, where the t represents the number of years since the study started. based on the function, what is the growth rate?
Answer: 0.045 is the growth rate.
Step-by-step explanation:
A generic exponential growth function can be written as:
f(t) = A*(1 + r)^t
where A is the initial amount.
t is the unit of time.
r is the rate of growth.
For example if we have an increase of 10% per year, with an initial population of 100 we have that:
A = 100, r = 10%/100% = 0.10, t = number of years.
the equation will be:
f(t) = 100*(1 + 0.10)^t
Now, in this case the equation is:
S(t) = 152*(1.045)^t
We can write this as:
S(t) = 152*(1 + 0.045)^t
Then 152 is the initial amount and 0.045 is the growth rate.
Assume that y varies directly with
x, then solve.
If y=6 when x=2/3 find x when y=12.
Х=? (It’s a fraction)
Answer:
x = 4/3
Step-by-step explanation:
Direct variation:
y = kx
We use the given x-y point to find k.
6 = k * 2/3
k = 6 * 3/2
k = 9
The equation is
y = 9x
For y = 12,
12 = 9x
x = 12/9
x = 4/3
Which table represents the inverse of the function defined above?
Hello!
Answer:
Table B.
Step-by-step explanation:
An inverse of a function means that the x and y values are swapped in comparison to the original function. For example:
We can use points on the table:
[tex]f(x)[/tex] = (7, 21)
The inverse of this function would 7 as its y value, and 21 as its x value:
[tex]f^{-1} (x)[/tex] = (21, 7)
The only table shown that correctly shows this relationship is table B.
Solve of the following equations for x: 2x = 4.
Answer:
[tex]\boxed{ x = 2}[/tex]
Step-by-step explanation:
=> [tex]2x = 4[/tex]
Dividing both sides by 2
=> [tex]\frac{2x}{2} = \frac{4}{2}[/tex]
=> x = 2
2x=4
x=4/2=2
.............
keith rented a truck for one day. There was a base fee of $15.95, there was an additional charge of 95 cents for each mile driven . keith had to pay $206.90 when he rented his truck. for how many miles did he drive the truck
Answer:
201 miles
Step-by-step explanation:
Base fee = $15.95
Mileage fee = $ 0.95 per/mile
Paid = $206.90
Distance= ?
--------------
Equation to calculate miles:
(206.90 - 15.95)/0.95= 201 milesAn investigation of a number of automobile accidents revealed the following information:
18 accidents involved alcohol and excessive speed.
26 involved alcohol.
12 accidents involved excessive speed but not alcohol.
21 accidents involved neither alcohol nor excessive speed.
How many accidents were investigated?
Answer:
59 accidents were investigated.
Step-by-step explanation:
The question above is a probability question that involves 2 elements: causes of accidents.
Let
A = Alcohol
E = Excessive speed
In the question, we are given the following information:
18 accidents involved Alcohol and Excessive speed =P(A ∩ E)
26 involved Alcohol = P(A)
12 accidents involved excessive speed but not alcohol = P( E ) Only
21 accidents involved neither alcohol nor excessive speed = neither A U B
We were given P(A) in the question. P(A Only) = P(A) - P(A ∩ E)
P(A Only) = 26 - 18
= 8
So, only 8 accident involved Alcohol but not excessive speed.
The Total number of Accidents investigated = P(A Only) + P( E only) + P(A ∩ E) + P( neither A U B)
= 8 + 12 + 18 + 21
= 59
Therefore, 59 accidents were investigated.
In a large University, the average age of all the students is 24 years with a standard deviation of 9 years. A random sample of 36 students is selected. a) Determine the standard error of the mean. b) What is the probability that the sample mean will be larger than 19.5
Answer:
-0.5
Step-by-step explanation:
σM=σ/√N
=9/√36
=9/6
=3/2=1.5
Z=(x-μ)/σ/√N
=(19.5-24)/9/√36
=-4.5/1.5=-3
The probability that the sample mean will be larger than 19.5 = -0.5
P(>19.5)=P(Z>-3)= -0.5
The first step for deriving the quadratic formula from the quadratic equation, 0 = ax2 + bx + c, is shown. Step 1: –c = ax2 + bx Which best explains or justifies Step 1?
Answer:
Subtract c from each side, using the subtraction property of equality
Step-by-step explanation:
0 = ax^2 + bx + c
Subtract c from each side, using the subtraction property of equality
-c = ax^2 + bx + c-c
-c = ax^2 + bx
Answer:
subtract c from each side, so the answer would be D
Find the total area of the prism.
Answer:
[tex]\boxed{\mathrm{864 \: in^2}}[/tex]
Step-by-step explanation:
The shape is a cube.
Apply formula for total surface area of cube.
[tex]SA=6a^2[/tex]
[tex]SA=\mathrm{total \: surface \: area}\\ a =\mathrm{side \: length}[/tex]
[tex]SA=6(12)^2[/tex]
[tex]SA=6(144)[/tex]
[tex]SA=864[/tex]
Answer:
[tex]\boxed{Area = 144 inches^2}[/tex]
Step-by-step explanation:
Area of a cube = Volume/Length
Where Length = 12 inches, Volume = 1728
Area = 1728/12
Area = 144 inches^2
Jeremy's father drives him to school in rush hour traffic in 20 minutes. One day there is no traffic, so his father can drive him 18 miles per hour faster and gets him to school in 12 minutes. How far (in miles) is it from Jeremy's home to school?
Answer:
9 miles
Step-by-step explanation:
Let's say that the speed that Jeremy's father drives Jeremy through traffic is x. When there is no traffic, Jeremy's father drives 18 miles per hour faster than his speed in traffic, x. This would make the speed that Jeremy's father drives Jeremy to school without traffic, 18 / 60 + x. This is as it is 18 miles per hour faster, not 18 miles per minute faster.
Now recall the formula Speed = Distance / Time, or S = D / T. We want the distance here ( How far (in miles) from Jeremy's home to school ) so let's isolate D here in this formula,
S = D / T ⇒ D = S [tex]*[/tex] T - and as you know, the distance from Jeremy's home to school is the same, with or without traffic. So, we can consider case 1 : Jeremy's " distance traveled " in traffic, and case 2 : Jeremy's " distance traveled " without traffic, and make them equal to one another.
20 [tex]*[/tex] x = 12 [tex]*[/tex] ( 18 / 60 + x ),
20x = 3.6 + 12x,
8x = 3.6,
x = 0.45 - Now the distance is 20 [tex]*[/tex] x, and hence 20 [tex]*[/tex] 0.45 = 9 miles
An amount of $21,000 is borrowed for 15 years at 7.75% Interest, compounded annually. If the loan is paid in full at the end of that period, how much must be
paid back?
round your answer to the nearest dollar.
Answer:
A=64340 dollars
Step-by-step explanation:
A=p(1+r)^t p principal, t= time period, r is the rate
A=21000(1+0.0775)^15= 64339.61
A=64340 dollars
Find f o g if f(x) = 3x^2 - 12 and g(x) = 5x + 3. f(g(x)) = Choices: a. 35x2 - 70 b. 15x2 - 30x + 9 c. 75x2 + 45x - 10 d. 75x2 + 90x + 15
Answer:
d.
Step-by-step explanation:
[tex]f(g(x))=3(g(x))^2-12=3(5x+3)^2-12=3(25x^2+30x+9)-12=75x^2+90x+27-12=75x^2+90x+15[/tex]
ASAP!!! NEED HELP!!!! Max is stacking logs at his campground for firewood. After his first load of logs, he has 8 logs on the stack. After his seventh load of logs, he has 62 logs on the stack. Use sequence notation to represent the arithmetic function. ANSWER CHOICES: A. an = 8 + 6(n − 1) B. an = 62 + 6(n − 1) C. an = 8 + 9(n − 1) D. an = 62 + 9(n − 1)
Answer: Choice C. an = 8 + 9(n-1)
===========================================
Work Shown:
a1 = 8 is the first term
a7 = 62 is the seventh term
an = a1+d(n-1) = nth term of arithmetic sequence
a7 = a1+d(7-1) ... plug in n = 7; solve for d
62 = 8+d(6)
62 = 6d+8
6d+8 = 62
6d = 62-8
6d = 54
d = 54/6
d = 9 is the common difference
an = a1 + d(n-1)
an = 8 + 9(n-1) is the nth term of this arithmetic sequence
Answer:
Choice C. an = 8 + 9(n-1)
Step-by-step explanation:
I just took the test
Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used. Match each sequence to its appropriate recursively defined function. f(1) = 13 f(n) = f(n - 1) + 26 for n ≥ 2 f(1) = 13 f(n) = 3 · f(n - 1) for n ≥ 2 f(1) = -24 f(n) = -4 · f(n - 1) for n ≥ 2 f(1) = 28 f(n) = f(n - 1) - 84 for n ≥ 2 f(1) = 28 f(n) = -4 · f(n - 1) for n ≥ 2 f(1) = -24 f(n) = 4 · f(n - 1) for n ≥ 2 Sequence Recursively Defined Function -24, -96, -384, -1,536, ... 28, -112, 448, -1,792, ... 13, 39, 65, 91, ...
Answer:
sequence 3no matching sequenceno matching sequenceno matching sequencesequence 2sequence 1Step-by-step explanation:
Recursively Defined Function Sequence
f(1) = 13 f(n) = f(n - 1) + 26 for n ≥ 2 13, 39, 65, 91, ...
f(1) = 13 f(n) = 3 · f(n - 1) for n ≥ 2
f(1) = -24 f(n) = -4 · f(n - 1) for n ≥ 2
f(1) = 28 f(n) = f(n - 1) - 84 for n ≥ 2
f(1) = 28 f(n) = -4 · f(n - 1) for n ≥ 2 28, -112, 448, -1,792, ...
f(1) = -24 f(n) = 4 · f(n - 1) for n ≥ 2 -24, -96, -384, -1,536, ...
__
The initial values are easily seen. They match f(1). The recursive functions can be tested to see if they match the offered sequences.
sequence 1 has a common ratio of 4 (not -4)
sequence 2 has a common ratio of -4 (it is not arithmetic)
sequence 3 has a common difference of 26 (it is not geometric)
Answer:
1 is sequence 3
5 is sequence 2
6 is sequence 1
(These r not included in the test, so don't use them)
|
\ /
2 is no matching sequence
3 is no matching sequence
4 is no matching sequence
Step-by-step explanation:
PLATO
what is 20% of 50naira?
Answer:
10
Step-by-step explanation:
To find 20% of 50 you need to times 20 with 50 and divide by 100.
20×50÷100
=10
The following sample was obtained from a population with unknown parameters.
Scores: 13, 7, 6, 12, 0, 4
a. Compute the sample mean and standard deviation. (Note that these are descriptive values that summarize the sample data.)
b. Compute the estimated standard error for M. (Note that this is an inferential value that describes how accurately the sample mean represents the unknown population mean.)
Answer:
i think is 7
Step-by-step explanation:
The tee for the sixth hole on a golf course is 400 yards from the tee. On that hole, Marsha hooked her ball to the left, as sketched below. Find the distance between Marsha’s ball and the hole to the nearest tenth of a yard. Answer any time! :D
Answer:
181.8 yd
Step-by-step explanation:
The law of cosines is good for this. It tells you for triangle sides 'a' and 'b' and included angle C, the length of 'c' is given by ...
c^2 = a^2 +b^2 -2ab·cos(C)
For the given geometry, this is ...
c^2 = 400^2 +240^2 -2(400)(240)cos(16°) ≈ 33,037.75
c ≈ √33037.75 ≈ 181.8 . . . yards
Marsha's ball is about 181.8 yards from the hole.
Answer:
181.8 yds
Step-by-step explanation:
I got it correct on founders edtell
may someone assist me?
Answer:
15 is the answer.Step-by-step explanation:
The side lengths are equal - supposedly
30 25
? ?
25 + ? = 45
-25 - 25
? = 20
45 - 30 = 15
The question mark should be equal to 15.
Hope this helps,
Kavitha
Find the slope of the line passing through the points (-5, 3) and (7,9).
Answer:
[tex]\huge\boxed{slope=\dfrac{1}{2}=0.5}[/tex]
Step-by-step explanation:
The formula of a slope:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
We have the points
[tex](-5;\ 3)\to x_1=-5;\ y_1=3\\(7;\ 9)\to x_2=7;\ y_2=9[/tex]
Substitute:
[tex]m=\dfrac{9-3}{7-(-5)}=\dfrac{6}{7+5}=\dfrac{6}{12}=\dfrac{6:6}{12:6}=\dfrac{1}{2}[/tex]
Answer:
1/2
Step-by-step explanation:
We can use the slope formula since we have 2 points
m = ( y2-y1)/(x2-x1)
= (9-3)/( 7 - -5)
= (9-3) /( 7+5)
= 6/ 12
= 1/2
Write an expression:
a) 4 less than twice a
number
11
Gra
ine
a)
e
Answer:
2x - 4.
Step-by-step explanation:
4 less than twice a number is the same thing as a number times 2 minus 4. Let's say that the number is represented by x.
2 * x - 4 = 2x - 4.
Hope this helps!
Different hotels in a certain area are randomly selected, and their ratings and prices were obtained online. Using technology, with x representing the ratings and y representing price, we find that the regression equation has a slope of 130 and a y-intercept of 350. Complete parts (a) and (b) below.
a. What is the equation of the regression line?
b. What does the symbol y represent?
A. The symbol y represents the average price of hotels in the area.
B. The symbol ý represents the amount that price increases with a 1-point increase in rating.
C. The symbol y represents the predicted value of price
D. The symbol y represents the expected price when the hotel's rating is 0
Answer:
a) Y = 350 + 130X
b) C. The symbol [tex]\hat {y}[/tex] represents the predicted value of price.
Step-by-step explanation:
The equation of a regression line is given as:
Y = a + bX
Where Y is the dependent variable, X is the independent variable, a is the intercept on the y axis when X = 0 and b is the slope of the regression line.
a) The regression equation has a slope of 130 and a y-intercept of 350. From Y = a + bX, the equation of the regression line is:
Y = 350 + 130X
b) From the question x represents the ratings of different hotels in a certain area and [tex]\hat {y}[/tex] represents the price of the different hotels based on their ratings. Since a regression line is drawn, y represents the predicted value of price
Find the distance between the points by filling in the steps. The first one is done for you.
Answer:
Q.2 [tex]4\sqrt2[/tex] units
Q.3 [tex]10\sqrt2[/tex] units
Step-by-step explanation:
Given that points:
C(-1, 3) and D (-5, 7)
E(0, -5) and F(10, -15)
To find:
Q.2. Distance between C and D
Q.3. Distance between E and F
Solution:
First of all, let us solve the question marked as number 2 in the attached image.
C(-1, 3) and D (-5, 7)
[tex]x_2 = -5\\x_1 = -1\\y_2 = 7\\y_1 = 3[/tex]
To find the distance 'd' between the points, we can use distance formula:
[tex]d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
[tex]d = \sqrt{(-5-(-1))^2+(7-3)^2}\\\Rightarrow d = \sqrt{(-4)^2+(4)^2}\\\Rightarrow d =\sqrt{16+16}\\\Rightarrow d =\sqrt{32} = 4\sqrt2\ units[/tex]
First of all, let us solve the question marked as number 3 in the attached image.
E(0, -5) and F(10, -15)
[tex]x_2 = 10\\x_1 = 0\\y_2 = -15\\y_1 = -5[/tex]
To find the distance 'd' between the points, we can use distance formula:
[tex]d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
[tex]d = \sqrt{(10-0)^2+(-15-(-5))^2}\\\Rightarrow d = \sqrt{10^2+(-10)^2}\\\Rightarrow d =\sqrt{100+100}\\\Rightarrow d =\sqrt{200} = 10\sqrt2\ units[/tex]
Please find attached image for the answers filled in the boxes.
The principal of a middle school claims that test scores of the seventh-graders at his school vary less than the test scores of the seventh-graders at a neighboring school, which have variation described by σ = 14.7. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms.
Answer:
There is sufficient evidence to support the claim that the standard deviation is less than 14.7.
Step-by-step explanation:
From the question we are told that that the null hypothesis is
[tex]H_o : \sigma < 14.7[/tex]
Now given from the question that this null hypothesis was rejected, it mean, in non technical term that there is sufficient evidence to support the claim that the standard deviation is less than 14.7.