Question 1

An example of dependent samples occurs when subjects are randomly assigned to the experimental and control groups of an experiment.

Accepted Answer

A) True 
 B)False  False

Question 2

The pooled-variances t-test requires the assumption that the two population ___________________________________ are equal,and that the populations are at least ___________________________________ distributed.

Accepted Answer

standard deviations; approximately normally

Question 3

Traffic Coordinator
A traffic coordinator for a community wishes to determine whether or not there is any difference in the average age of female and male drivers involved in rear-end accidents.The hypothesis test is: HS1U1B10S1U1B0: $\mu _ { 1 } = \mu _ { 2 }$ (no difference in mean age)
HS1U1B11S1U1B0: $\mu _ { 1 } \neq \mu _ { 2 }$ (mean age is different)A random sample of males and females involved in rear-end accidents results in the following Minitab summary: $$\begin{array} { l c c c c c c } 
& \text { N } & \text { MEAN } & \text { MEDIAN } & \text { TRMEAN } & \text { STDEV } & \text { SEMEAN } \
\text { FEMALES } & 33 & 23.91 & 20.00 & 23.38 & 9.77 & 1.70 \
\text { MALES } & 38 & 28.87 & 28.50 & 28.44 & 9.67 & 1.57
\end{array}$$
-What is the conclusion?

Accepted Answer

Do not reject H₀ There is not enough statistical evidence to say that there is a difference in the average age of female and male drivers involved in rear-end accidents.

Question 4

A political analyst in Texas surveys a random sample of registered Democrats and compares the results with those obtained from a random sample of registered Republicans.This would be an example of:

Accepted Answer

A)  Independent samples. 
B)  dependent samples. 
C)  Independent samples only if the sample sizes are equal. 
D)  Dependent samples only if the sample sizes are equal. 
A)  Independent samples. 
B)  dependent samples. 
C)  Independent samples only if the sample sizes are equal. 
D)  Dependent samples only if the sample sizes are equal.

Question 5

Golf ball
A new golf ball has been designed to improve driving distance off the tee when compared to their market competitor.To test their new ball,nine golfers hit a drive with the current ball and then hit another drive with the new ball.The distance in yards for each golfer is shown in the following table.
 $$\begin{array} { | c | c | } 
\hline \begin{array} { c } 
\text { Current Golf Ball } \
\text { (Pupulation 1) }
\end{array} & \begin{array} { c } 
\text { New Golf Ball } \
\text { (Population 2) }
\end{array} \
\hline 212 & 215 \
\hline 236 & 228 \
\hline 250 & 256 \
\hline 243 & 264 \
\hline 250 & 248 \
\hline 235 & 255 \
\hline 230 & 239 \
\hline 225 & 218 \
\hline 220 & 239 \
\hline
\end{array}$$
-Use $\alpha$ = 0.05.What is your conclusion?

Accepted Answer

Since t = -1.789,we fail to re

Question 6

Medicare
An economist wishes to test whether there is any difference in the proportion of households receiving Medicare for white households with less than $5,000 income per year and white households with $15,000 or more income per year.A random sample from households with less than $5,000 income per year is taken,and a random sample of households with $15,000 or more income is taken.The results of the samples are: $$\begin{array} { | l | c c | } 
\hline & \text { Less than } \$ \mathbf { 5 , 0 0 0 } & \mathbf { \$ 1 5 , 0 0 0 } \text { or more } \
\hline \text { Sample size } & 200 & 150 \
\text { Medicare Recipients } & 157 & 139 \
\hline
\end{array}$$
-Use a 0.01 significance level to determine if there is sufficient evidence to conclude that a difference in proportions exists.What is the value of the test statistic?
Appropriate test: ____________________
Test statistic = ____________________

Accepted Answer

The answer of Medicare
An economist wishes to test whether there...

Question 7

Ford Motor Co.
The Ford Motor Company,as part of its quality control program,began returning to the supplier all shipments of steel that had defects or faulty chemistry.When Ford began this program,the defective rate in 100 shipments was 9%.A recent survey indicated that 2.2% in 136 shipments was defective.Does this represent a significant improvement in the quality of the steel? Test at the 0.05 level.
-What is the conclusion?

Accepted Answer

Reject H₀ There is enough evide

Question 8

The ____________________ approximation is an alternative to the unequal-variances t-test whenever both n1 and n2 are ≥ 30.

Accepted Answer

Question 9

When testing dependent samples,we test for only one variable.What is it?

Accepted Answer

d = Differ

Question 10

Population
In an effort to test the hypothesis that the proportion of home ownership in the state of Delaware is different than the national proportion,the following data was collected.
 $$\begin{array} { | l | c | c | } 
\hline \text { Population } & \text { Number of Home Owners } & \text { Sample Size } \
\hline \text { Delaware } & 310 & 500 \
\hline \text { Nation } & 390 & 600 \
\hline
\end{array}$$
-Use $\alpha$ = 0.01.State the decision rule in terms of the critical value.

Accepted Answer

If -2.57 @#LAT-DLM&z@#LAT-DLM&  2.57, fa

Question 11

Battery
A new brand of battery for use in calculators and cameras is said to last significantly longer than another brand.A camera manufacturer is to test this brand (Y)with brand (X)to see if brand Y has a longer life.If brand Y does last longer,the camera manufacturer will equip their new cameras with them.If not,they will equip them with brand X that is less costly.Twenty cameras are equipped as follows: ten with brand Y batteries and ten with brand X batteries and the life of the batteries measured.Is brand Y superior (does it last longer)to brand X? To answer this question,the camera manufacturer uses a 0.01 significance level and knows that the populations are normally distributed with equal variances.Sample data are: $$\begin{array} { | c | c | } 
\hline \text { Brand } \boldsymbol { X } & \text { Brand } \boldsymbol { Y } \
\hline n _ { 1 } = 10 & n _ { 2 } = 10 \
\bar { x } _ { 1 } = 500 \text { hours } & \bar { x } _ { 2 } = 650 \text { hours } \
s _ { 1 } ^ { 2 } = 400 & s _ { 2 } ^ { 2 } = 484 \
\hline
\end{array}$$
-State the conclusion.

Accepted Answer

Reject H₀ The evidence points t

Question 12

Traffic Coordinator
A traffic coordinator for a community wishes to determine whether or not there is any difference in the average age of female and male drivers involved in rear-end accidents.The hypothesis test is: HS1U1B10S1U1B0: $\mu _ { 1 } = \mu _ { 2 }$ (no difference in mean age)
HS1U1B11S1U1B0: $\mu _ { 1 } \neq \mu _ { 2 }$ (mean age is different)A random sample of males and females involved in rear-end accidents results in the following Minitab summary: $$\begin{array} { l c c c c c c } 
& \text { N } & \text { MEAN } & \text { MEDIAN } & \text { TRMEAN } & \text { STDEV } & \text { SEMEAN } \
\text { FEMALES } & 33 & 23.91 & 20.00 & 23.38 & 9.77 & 1.70 \
\text { MALES } & 38 & 28.87 & 28.50 & 28.44 & 9.67 & 1.57
\end{array}$$
-What is the value of the test statistic?
Appropriate test: ____________________
Test statistic = ____________________

Accepted Answer

The answer of Traffic Coordinator
A traffic coordinator for a community...

Question 13

A test that we can use to determine whether two population variances are equal is the ____________________.

Accepted Answer

The answer of A test that we can use to...

Question 14

When comparing the means of two independent samples,the ____________________ is applicable whenever the population standard deviations are unknown.

Accepted Answer

The answer of When comparing the means of two independent...

Question 15

Although it is often associated only with small-sample tests,the t distribution is appropriate when the population standard deviations are unknown,regardless of how large or small the samples happen to be.

Accepted Answer

A) True 
 B)False

Question 16

Production Line
A quality control inspector keeps a tally sheet of the number of acceptable and unacceptable products that come off two different production lines.The completed sheet is shown below. $$\begin{array}{l}
\text { Products }\
\begin{array} { | c | c c | } 
\hline \text { Production line } & \text { Acceptable } & \text { Unacceptable } \
\hline 1 & 152 & 48 \
2 & 136 & 54 \
\hline
\end{array}
\end{array}$$
What is the p-value of the test?

Accepted Answer

The answer of Production Line
A quality control inspector keeps a...

Question 17

If we wish to compare the before-and-after reading speeds of individual participants in a speed-reading course,the z-test for comparing the means of two independent samples is appropriate.

Accepted Answer

A) True 
 B)False

Question 18

The F distribution is the sampling distribution of $s _ { 1 } ^ { 2 } / s _ { 2 } ^ { 2 }$ that would result if two samples were repeatedly drawn from the same,normally distributed population.

Accepted Answer

A) True 
 B)False

Question 19

Slacks Manufacturer
A slacks manufacturer is deciding whether to purchase a new method for bonding seams together.Before purchasing a new method that bonds,or glues,the seams together,the manufacturer wishes to determine whether or not the "bonded" seams can withstand more pulling stress than standard seams sewn with thread.The creator of the new method provides a demonstration machine and supplies for the slacks maker to test.Two samples of the slacks produced are taken.Each pair of slacks has the seams tested in an application of force to determine the breaking point (in lbs.)for the seam.The sample results are: $$\begin{array} { | c | c | } 
\hline \text { Sample 1: Sewn } & \text { Sample 2: Glued } \
\hline n _ { 1 } = 50 & n _ { 2 } = 50 \
\bar { x } _ { 1 } = 125 \mathrm { Ibs } . & \bar { x } _ { 2 } = 165 \mathrm { Ibs } . \
s _ { 1 } = 46 \mathrm { Ibs } . & s _ { 2 } = 57 \mathrm { Ibs } . \
\hline
\end{array}$$
-The test question is: At the 0.05 level of significance,is the gluing of seams better than sewing? What are the null and alternative hypotheses?
H0: ____________________
H1: ____________________

Accepted Answer

Question 20

National Management Assoc
The National Management Association reports that during the past year,there has been a substantial increase in the use of "flextime" in the work place.Last year,a sample of 100 businesses was taken which indicated that 22% had implemented the use of "flextime." This year,a second survey of 100 showed that 29% were using flextime.At the 0.05 level,does this represent an increase in the proportion?
-State the conclusion.

Accepted Answer

Do not reject H₀ Ther

An example of dependent samples occurs when subjects are randomly assigned to the experimental and control groups of an experiment.

The pooled-variances t-test requires the assumption that the two population _ are equal,and that the populations are at least _ distributed.

A political analyst in Texas surveys a random sample of registered Democrats and compares the results with those obtained from a random sample of registered Republicans.This would be an example of:

The ____________________ approximation is an alternative to the unequal-variances t-test whenever both n₁ and n₂ are ≥ 30.

When testing dependent samples,we test for only one variable.What is it?

A test that we can use to determine whether two population variances are equal is the ____________________.

When comparing the means of two independent samples,the ____________________ is applicable whenever the population standard deviations are unknown.

Although it is often associated only with small-sample tests,the t distribution is appropriate when the population standard deviations are unknown,regardless of how large or small the samples happen to be.

Production Line A quality control inspector keeps a tally sheet of the number of acceptable and unacceptable products that come off two different production lines.The completed sheet is shown below. Products Production line Acceptable Unacceptable 1 152 48 2 136 54 What is the p-value of the test?

If we wish to compare the before-and-after reading speeds of individual participants in a speed-reading course,the z-test for comparing the means of two independent samples is appropriate.

The F distribution is the sampling distribution of $s _ { 1 } ^ { 2 } / s _ { 2 } ^ { 2 }$ that would result if two samples were repeatedly drawn from the same,normally distributed population.

A Preview of Business Statistics

Visual Description of Data

Statistical Description of Data

Data Collection and Sampling Methods

Probability: Review of Basic Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Estimation From Sample Data

Hypothesis Tests Involving a Sample Mean or Proportion

Analysis of Variance Tests

Chi-Square Applications

Nonparametric Methods

Simple Linear Regression and Correlation

Multiple Regression and Correlation

Model Building

Models for Time Series and Forecasting

Decision Theory

Total Quality Management

Filters

Exam 11: Hypothesis Tests Involving Two Sample Means

An example of dependent samples occurs when subjects are randomly assigned to the experimental and control groups of an experiment.

The pooled-variances t-test requires the assumption that the two population ___________________________________ are equal,and that the populations are at least ___________________________________ distributed.

A political analyst in Texas surveys a random sample of registered Democrats and compares the results with those obtained from a random sample of registered Republicans.This would be an example of:

The ____________________ approximation is an alternative to the unequal-variances t-test whenever both n1 and n2 are ≥ 30.

When testing dependent samples,we test for only one variable.What is it?

A test that we can use to determine whether two population variances are equal is the ____________________.

When comparing the means of two independent samples,the ____________________ is applicable whenever the population standard deviations are unknown.

Although it is often associated only with small-sample tests,the t distribution is appropriate when the population standard deviations are unknown,regardless of how large or small the samples happen to be.

Production Line A quality control inspector keeps a tally sheet of the number of acceptable and unacceptable products that come off two different production lines.The completed sheet is shown below. Products Production line Acceptable Unacceptable 1 152 48 2 136 54 What is the p-value of the test?

If we wish to compare the before-and-after reading speeds of individual participants in a speed-reading course,the z-test for comparing the means of two independent samples is appropriate.

The F distribution is the sampling distribution of s12/s22s _ { 1 } ^ { 2 } / s _ { 2 } ^ { 2 }s12​/s22​ that would result if two samples were repeatedly drawn from the same,normally distributed population.

A Preview of Business Statistics

Visual Description of Data

Statistical Description of Data

Data Collection and Sampling Methods

Probability: Review of Basic Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Estimation From Sample Data

Hypothesis Tests Involving a Sample Mean or Proportion

Analysis of Variance Tests

Chi-Square Applications

Nonparametric Methods

Simple Linear Regression and Correlation

Multiple Regression and Correlation

Model Building

Models for Time Series and Forecasting

Decision Theory

Total Quality Management

Filters

The pooled-variances t-test requires the assumption that the two population _ are equal,and that the populations are at least _ distributed.

The ____________________ approximation is an alternative to the unequal-variances t-test whenever both n₁ and n₂ are ≥ 30.

The F distribution is the sampling distribution of $s _ { 1 } ^ { 2 } / s _ { 2 } ^ { 2 }$ that would result if two samples were repeatedly drawn from the same,normally distributed population.