Question 1

Find $S _ { d }$ Consider the set of differences between two dependent sets:  84,85,83,63,61,100,98 . Round to the nearest tenth.

Accepted Answer

A)   15.3 
B)   16.2 
C)   15.7 
D)   13.1 
A)   15.3 
B)   16.2 
C)   15.7 
D)   13.1

Question 2

When performing a hypothesis test for the ratio of two population variances, the upper critical  F  value is denoted $F _ { R }$ The lower critical  F  value, $F _ { \mathrm { L } , }$ can be found as follows: interchange the degrees of freedom, and then take the reciprocal of the resulting  F  value found in Table A-5. $\bar { F } _ { B }$ can be denoted $F _ { \alpha / 2 }$ and $F _ { L }$ can be denoted $F _ { 1 - \alpha / 2 }$
Find the critical values  $F _ { L }$ and  $F _ { R }$ for a two-tailed hypothesis test based on the following values: $n _ { 1 } = 25 , n _ { 2 } = 16 , \alpha = 0.10$

Accepted Answer

A)   0.7351,2.2378 
B)   0.5327,2.2878 
C)   0.4745,2.2878 
D)   0.4745,2.4371 
A)   0.7351,2.2378 
B)   0.5327,2.2878 
C)   0.4745,2.2878 
D)   0.4745,2.4371

Question 3

Assume that you want to test the claim that the paired sample data come from a population for which the mean difference is $\mu _ { d } = 0$
Compute the value of the  t  test statistic. Round intermediate calculations to four decimal places as needed and final answers to three decimal places as needed.
$\begin{array} { l | c c c c c c c c c } 
\text { Subject } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } & \text { G } & \text { H } & \text { I } \
\hline \text { Before } & 168 & 180 & 157 & 132 & 202 & 124 & 190 & 210 & 171 \
\hline \text { After } & 162 & 178 & 145 & 125 & 171 & 126 & 180 & 195 & 163
\end{array}$

Accepted Answer

A)   9.468 
B)   3.156 
C)   0.351 
D)   1.052 
A)   9.468 
B)   3.156 
C)   0.351 
D)   1.052

Question 4

Assume that two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Which distribution is used to test the claim that women have a higher mean resting heart rate Than men?

Accepted Answer

A)  Normal 
B)  t 
C)  chi-square 
D)  F 
A)  Normal 
B)  t 
C)  chi-square 
D)  F

Question 5

Determine whether the samples are dependent or independent. The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient.

Accepted Answer

A)  Dependent samples 
B)  Independent samples 
A)  Dependent samples 
B)  Independent samples

Question 6

Test the given claim about the means of two populations. Assume that two dependent samples have been randomly selected from normally distributed populations. A test of abstract reasoning is given to a random sample of students before and after they completed a formal logic course. The results are given below. At the  0.05  significance level, test the claim that the mean score is not affected by the course. Include your null and alternative hypotheses, the test statistic,  P -value or critical value(s), conclusion about the null hypothesis, and conclusion about the claim in your answer.
$\begin{array} { l c c c c c c c c c c } 
\text { Before } & 74 & 83 & 75 & 88 & 84 & 63 & 93 & 84 & 91 & 77 \
\hline \text { After } & 73 & 77 & 70 & 77 & 74 & 67 & 95 & 83 & 84 & 75
\end{array}$

Accepted Answer

@#LAT-DLM&
Test statistic  t=2.366 . Cri

Question 7

If the lengths of male skis and female skis are used to construct a  95%  confidence interval for the difference between the two population means, the result is
 14.32 cm $< \mu _ { 1 } - \mu _ { 2 } < 21.95 \mathrm {~cm}$
where lengths of male skis correspond to population 1 and engths of female skis correspond to population 2. Express the confidence interval with the engths of female skis being population 1 and lengths of male skis being population

Accepted Answer

A)  $14.32 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < 21.95 \mathrm {~cm}$ 
B)  $- 14.32 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < - 21.95 \mathrm {~cm}$ 
C)  $- 21.95 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < - 14.32 \mathrm {~cm}$ 
D)  This cannot be determined without having the original data values. 
A)  $14.32 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < 21.95 \mathrm {~cm}$ 
B)  $- 14.32 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < - 21.95 \mathrm {~cm}$ 
C)  $- 21.95 \mathrm {~cm} < \mu _ { 1 } - \mu _ { 2 } < - 14.32 \mathrm {~cm}$ 
D)  This cannot be determined without having the original data values.

Question 8

Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. A paint manufacturer wished to compare the drying times of two different types of paint. Independent simple random samples of 11 cans of type  A and 9 cans of type  B were selected and applied to similar surfaces. The drying times, in hours, were recorded. The summary statistics are as follows.
 
Construct a  98%  confidence interval for $\mu _ { 1 } - \mu _ { 2 }$ the difference between the mean drying time for paint of type A and the mean drying time for paint of type B.

Accepted Answer

A)  $6.08 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.72 \mathrm { hrs }$ 
B)  $5.92 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.88 \mathrm { hrs }$ 
C)  $5.85 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.95 \mathrm { hrs }$ 
D)  $5.78 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 17.02 \mathrm { hrs }$ 
A)  $6.08 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.72 \mathrm { hrs }$ 
B)  $5.92 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.88 \mathrm { hrs }$ 
C)  $5.85 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.95 \mathrm { hrs }$ 
D)  $5.78 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 17.02 \mathrm { hrs }$

Question 9

Determine the decision criterion for rejecting the null hypothesis in the given hypothesis test; i.e., describe the values of the test statistic that would result in rejection of the null hypothesis. We wish to compare the means of two populations using paired observations. Suppose that $\bar { d } = 3.125 , s _ { d } = 2.911$
and  n=8 , and that you wish to test the following hypothesis at the
 10 %  level of significance:
$H _ { 0 } : \mu _ { d } = 0 \text { against } H _ { 1 } : \mu _ { d } > 0$
What decision rule would you use?

Accepted Answer

A)  Reject $H _ { 0 }$ if the test statistic is less than  1.415 . 
B)  Reject $H _ { 0 }$ if the test statistic is greater than  -1.145 . 
C)  Reject $H _ { 0 }$ if the test statistic is greater than  -1.145  or less than  1.415 . 
D)  Reject $H _ { 0 }$ if the test statistic is greater than  1.415 . 
A)  Reject $H _ { 0 }$ if the test statistic is less than  1.415 . 
B)  Reject $H _ { 0 }$ if the test statistic is greater than  -1.145 . 
C)  Reject $H _ { 0 }$ if the test statistic is greater than  -1.145  or less than  1.415 . 
D)  Reject $H _ { 0 }$ if the test statistic is greater than  1.415 .

Question 10

In the context of a hypothesis test for two proportions, which of the following statements about the pooled sample proportion, $\bar { p } ,$  is/are true?
I. It estimates the common value of text $p _ { 1 }$ and $p _ { 2 }$ under the assumption of equal proportions.
II. It is obtained by averaging the two sample proportions $\hat { p }$ and $\hat { p } _ { 2 }$
III. It is equal to the proportion of successes in both samples combined.

Accepted Answer

A)  I and II 
B)  III only 
C)  I, II, and III 
D)  I and III 
A)  I and II 
B)  III only 
C)  I, II, and III 
D)  I and III

Question 11

Test the indicated claim about the means of two populations. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal.
 
Use a  0.05  significance level to test the claim that the mean amount of time spent watching television by women is smaller than the mean amount of time spent watching television by men. Include your null and alternative hypotheses, the test statistic,  P -value or critical value(s), conclusion about the null hypothesis, and conclusion about the claim in your answer.

Accepted Answer

. At the  5% significance level, there i

Question 12

Express the alternative hypothesis in symbolic form. A professor claims that the mean amount of time (in hours) sophomores spent studying for the statistics final exam is more than that of freshmen. Assume that the two samples are independent. Let the freshmen be the first population and the sophomores be the second population.

Accepted Answer

A)  $H _ { 1 } : \mu _ { 1 } = \mu _ { 2 }$ 
B)  $H _ { 1 } : \mu _ { 1 }  \mu _ { 2 }$ 
D)  $H _ { 1 } : \mu _ { 1 } \neq \mu _ { 2 }$ 
A)  $H _ { 1 } : \mu _ { 1 } = \mu _ { 2 }$ 
B)  $H _ { 1 } : \mu _ { 1 }  \mu _ { 2 }$ 
D)  $H _ { 1 } : \mu _ { 1 } \neq \mu _ { 2 }$

Question 13

In a random sample of 300 women,  45%  favored stricter DUI legislation. In a random sample of 200 men,  25%  favored stricter DUI legislation. Construct a  95%  confidence interval for the difference between the population proportions $p _ { 1 } - p _ { 2 }$ . Assume that the samples are independent and that they have been randomly selected.

Accepted Answer

The answer of In a random sample of 300 women,...

Question 14

Find the number of successes x suggested by the given statement. A computer manufacturer randomly selects 2680 of its computers for quality assurance and finds that 1.98% of these computers are found to be defective.

Accepted Answer

A)  56 
B)  51 
C)  58 
D)  53 
A)  56 
B)  51 
C)  58 
D)  53

Question 15

Identify the test statistic that should be used for testing the following given claims. a. The mean of the differences between IQ scores of brothers and IQ scores of their sisters is
equal to 0.
b. The proportion of offices with windows is equal to the proportion of offices without
windows.
c. The variation among temperature inside buildings in winter is equal to the variation in the
temperature inside building in summer.
d. The mean age of female math professors is equal to the mean age of male math professors.

Accepted Answer

The answer of Identify the test statistic that should be...

Question 16

Construct a confidence interval for $\mu _ { d }$, the mean of the differences $d$ for the population of paired data. Assume that the population of paired differences is normally distributed. A test of writing ability is given to a random sample of students before and after they completed a formal writing course. The results are given below. Construct a  99%  confidence interval for the mean difference between the before and after scores.
$\begin{array} { l l l l l l l l l l l l } 
\text { Before } & 70 & 80 & 92 & 99 & 93 & 97 & 76 & 63 & 68 & 71 & 74 \
\hline \text { After } & 69 & 79 & 90 & 96 & 91 & 95 & 75 & 64 & 62 & 64 & 76
\end{array}$

Accepted Answer

A)  $- 0.5 < \mu _ { d } < 4.5$ 
B)  $- 0.2 < \mu _ { d } < 4.2$ 
C)  $- 0.1 < \mu _ { d } < 4.1$ 
D)  $1.2 < \mu _ { d } < 2.8$ 
A)  $- 0.5 < \mu _ { d } < 4.5$ 
B)  $- 0.2 < \mu _ { d } < 4.2$ 
C)  $- 0.1 < \mu _ { d } < 4.1$ 
D)  $1.2 < \mu _ { d } < 2.8$

Question 17

Assume that you plan to use a significance level of $\alpha = 0.05$ to test the claim that $p _ { 1 } = p _ { 2 }$ Use the given sample sizes and numbers of successes to find the pooled estimate $\bar { p }$ Round your answer to the nearest thousandth.
$\begin{array} { l l } 
n _ { 1 } = 100 & n _ { 2 } = 100 \
x _ { 1 } = 42 & x _ { 2 } = 45
\end{array}$

Accepted Answer

A)   0.479 
B)   0.435 
C)   0.305 
D)   0.392 
A)   0.479 
B)   0.435 
C)   0.305 
D)   0.392

Question 18

Assume marketing survey involves product recognition in New York and California. Of 558 New
Yorkers surveyed, 193 knew the product while 196 out of 614 Californians knew the product.
At the 0.05 significance level, test the claim that the recognition rates are the same in both
states. Include your null and alternative hypotheses, the test statistic, P-value or critical value(s),
conclusion about the null hypothesis, and conclusion about the claim in your answer.

Accepted Answer

@#LAT-DLM&.
Test statistic: @#LAT-DLM&. Critical v

Question 19

Determine whether the samples are dependent or independent. The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug.

Accepted Answer

A)  Dependent samples 
B)  Independent samples 
A)  Dependent samples 
B)  Independent samples

Question 20

Which distribution is used to test the claim that the standard deviation of the ages (in years)of when girls first learn to ride a bike is equal to the standard deviation of the ages (in years) when boys first lean to ride a bike?

Accepted Answer

A)  Normal 
B)  t 
C)  chi-square 
D)  F 
A)  Normal 
B)  t 
C)  chi-square 
D)  F

Find $S _ { d }$ Consider the set of differences between two dependent sets: 84,85,83,63,61,100,98 . Round to the nearest tenth.

Assume that two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Which distribution is used to test the claim that women have a higher mean resting heart rate Than men?

Determine whether the samples are dependent or independent. The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient.

Find the number of successes x suggested by the given statement. A computer manufacturer randomly selects 2680 of its computers for quality assurance and finds that 1.98% of these computers are found to be defective.

Assume that you plan to use a significance level of $\alpha = 0.05$ to test the claim that $p _ { 1 } = p _ { 2 }$ Use the given sample sizes and numbers of successes to find the pooled estimate $\bar { p }$ Round your answer to the nearest thousandth. =100 =100 =42 =45

Determine whether the samples are dependent or independent. The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug.

Which distribution is used to test the claim that the standard deviation of the ages (in years)of when girls first learn to ride a bike is equal to the standard deviation of the ages (in years) when boys first lean to ride a bike?

Introduction to Statistics

Exploring Data With Tables and Graphs

Describing, Exploring, and Comparing Data

Probability

Discrete Probability Distributions

Normal Probability Distributions

Estimating Parameters and Determining Sample Sizes

Hypothesis Testing

Correlation and Regression

Goodness-Of-Fit and Contingency Tables

Analysis of Variance

Nonparametric Tests

Statistical Process Control

Filters

Exam 9: Inferences From Two Samples

Find SdS _ { d }Sd​ Consider the set of differences between two dependent sets: 84,85,83,63,61,100,98 . Round to the nearest tenth.

Assume that two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Which distribution is used to test the claim that women have a higher mean resting heart rate Than men?

Determine whether the samples are dependent or independent. The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient.

Find the number of successes x suggested by the given statement. A computer manufacturer randomly selects 2680 of its computers for quality assurance and finds that 1.98% of these computers are found to be defective.

Determine whether the samples are dependent or independent. The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug.

Which distribution is used to test the claim that the standard deviation of the ages (in years)of when girls first learn to ride a bike is equal to the standard deviation of the ages (in years) when boys first lean to ride a bike?

Introduction to Statistics

Exploring Data With Tables and Graphs

Describing, Exploring, and Comparing Data

Probability

Discrete Probability Distributions

Normal Probability Distributions

Estimating Parameters and Determining Sample Sizes

Hypothesis Testing

Correlation and Regression

Goodness-Of-Fit and Contingency Tables

Analysis of Variance

Nonparametric Tests

Statistical Process Control

Filters

Find $S _ { d }$ Consider the set of differences between two dependent sets: 84,85,83,63,61,100,98 . Round to the nearest tenth.