Description of this paper

GBS 221 Business Statistics Final Exam Part 1

Description

solution..


Question

Question

 

Introduction

 

 

GBS221

 

 

Business Statistics

 

 

Final Exam Part 1

 

 

Your exam is comprised of two parts. The first part has40 multiple-choice questions worth 4 points each. The second part has 10 questions worth 4 points. There are 200 total points for this exam. You may use a calculator for this exam.

 

 

As you work through the exam, the program will automatically save your work. However, you may also save more frequently by selecting the SAVE button located at the end of the assessment. This is a timed exam. You will be given 1.5 hours in which to complete part 1, and 1.5 hour in which to complete part 2. There is a timer in the upper right hand corner of the exam to help you keep track. After 1.5 hours have passed, part 1 of the exam will automatically be saved and submitted. Once the exam has been submitted, the program will close.

 

 

Please make sure you have answered all questions in Part 1 prior to submitting them. Once they are submitted, you willnot be able to return to that section.

 

 

Question

 

 

1of40

 

 

If the hypothesis test is used in a quality control setting, the alternative hypothesis takes the stance that the process is not behaving as it should and needs some sort of attention

 

 

True

 

 

False

 

 

Question

 

 

2of40

 

 

A Type II error is known as the producer\\\'s risk because, when it occurs in quality control settings, the producer is looking for a problem in its process that does not exist

 

 

True

 

 

False

 

 

Question

 

 

3of40

 

 

CoStar would like to test if the vacancy rate for warehouse stores is more than 8%. The correct hypothesis statement to test for this vacancy rate would be

 

 

H0:? ?0.08; H1:?> 0.08.

 

 

H0:?= 0.08; H1:? ?0.08.

 

 

H0:? ?0.08; H1:?= 0.08.

 

 

H0:?= 0.08; H1:?< 0.08.

 

 

Question

 

 

4of40

 

 

CoStar would like to test if the vacancy rate for warehouse stores is more than 8%. A Type I error would occur if CoStar concludes that the vacancy rate was

 

 

more than 8% when, in reality, the proportion was 8% or less.

 

 

8% or less when, in reality, the proportion was more than 8%.

 

 

equal to 8% when, in reality, the proportion was 8% or less.

 

 

not equal to 8% when, in reality, the proportion was equal to 8%.

 

 

Question

 

 

5of40

 

 

The p-value for a hypothesis test is defined as the probability of observing a

 

 

critical value at least as extreme as the one selected for the hypothesis test, assuming the null hypothesis is true.

 

 

critical value at least as extreme as the one selected for the hypothesis test, assuming the null hypothesis is false.

 

 

sample mean at least as extreme as the one selected for the hypothesis test, assuming the null hypothesis is true.

 

 

population mean at least as extreme as the one selected for the hypothesis test, assuming the alternative hypothesis is true.

 

 

Question

 

 

6of40

 

 

The Department of Education would like to test the hypothesis that the average debt load of graduating students with a bachelor\\\'s degree equals $17,000. A random sample of 34 students had an average debt load of $18,200. It is believed that the population standard deviation for student debt load is $4,200. The Department of Education would like to set?= 0.05. The critical value for this hypothesis test would be ________.

 

 

-1.96

 

 

±1.645

 

 

1.645

 

 

±1.96

 

 

Question

 

 

7of40

 

 

Sony would like to test the hypothesis that the average age of a PlayStation user differs from the average age of an Xbox user. A random sample of 32 PlayStation users had an average age of 33.7 years while a random sample of 36 Xbox users had an average age of 35.6 years. Assume that the population standard deviation for the age of PlayStation and Xbox users is 3.7 and 3.5 years, respectively. Sony would like to set?= 0.05. The critical value for this hypothesis test would be ________.

 

 

1.28

 

 

-1.645

 

 

±1.96

 

 

2.33

 

 

Question

 

 

8of40

 

 

Sony would like to test the hypothesis that the average age of a PlayStation user differs from the average age of an Xbox user. A random sample of 32 PlayStation users had an average age of 33.7 years while a random sample of 36 Xbox users had an average age of 35.6 years. Assume that the population standard deviation for the age of PlayStation and Xbox users is 3.7 and 3.5 years, respectively. Sony would like to set?= 0.05. If Population 1 is defined as PlayStation users and Population 2 is defined as Xbox users, the test statistic for this hypothesis test would be ________.

 

 

= 1.29

 

 

= -1.13

 

 

= 1.89

 

 

= -2.17

 

 

Question

 

 

9of40

 

 

The federal government would like to test the hypothesis that the average age of men filing for Social Security is higher than the average age of women filing, using?= 0.05 with the following data:

 

 

 

 

If Population 1 is defined as men and Population 2 is defined as women, the test statistic for this hypothesis test would be ________.

 

 

= 1.19

 

 

= -1.78

 

 

= 2.07

 

 

= -2.23

 

 

Question

 

 

10of40

 

 

Two real estate companies, Century 21 and RE/MAX, compete with one another in a local market. The manager of the Century 21 office would like to advertise that homes listed with RE/MAX average greater than 10 days more on the market when compared to homes listed with his company. The following data show the sample size and average number of days on the market for the two companies along with the population standard deviations.

 

 

 

 

If Population 1 is defined as RE/MAX and Population 2 is defined as Century 21, the 80% confidence interval for the difference in population means is ________.

 

 

(17.8, 26.2)

 

 

(11.5, 32.7)

 

 

(5.4, 38.6)

 

 

(-3.0, 47.0)

 

 

Question

 

 

11of40

 

 

The Wall Street Journal reported that the average amount of time that a French person spends eating lunch at a restaurant is 22 minutes. Perform a hypothesis test to determine if a difference exists between the average time an American spends eating lunch and the average time a person from France spends eating lunch. The following data represent the time, in minutes, that random French and American diners spent at lunch. Assume that the population variances are equal.

 

 

 

 

If Population 1 is defined as French diners and Population 2 is defined as American diners, the 90% confidence interval for the difference in population means is ________.

 

 

(-0.75, 6.75)

 

 

(1.93, 4.06)

 

 

(1.52, 4.49)

 

 

(-3.36, 9.36)

 

 

Question

 

 

12of40

 

 

The Wall Street Journal reported that the average amount of time that a French person spends eating lunch at a restaurant is 22 minutes. Perform a hypothesis test to determine if a difference exists between the average time an American spends eating lunch and the average time a person from France spends eating lunch. The following data represent the time, in minutes, that random French and American diners spent at lunch. Assume that the population variances are equal.

 

 

 

 

If Population 1 is defined as French diners and Population 2 is defined as American diners, which one of the following statements is true?

 

 

Because the 90% confidence interval does not include zero, you can conclude that the average time an American spends at lunch equals the average time that French diners spend at lunch.

 

 

Because the 90% confidence interval does not include zero, you can conclude that the average time an American spends at lunch differs from the average time that French diners spend at lunch.

 

 

Because the 90% confidence interval includes zero, you can conclude that the average time an American spends at lunch differs from the average time that French diners spend at lunch.

 

 

Because the 90% confidence interval includes zero, you cannot conclude that the average time an American spends at lunch differs from the average time that French diners spend at lunch.

 

 

Question

 

 

13of40

 

 

Analysis of variance is a technique used to conduct a hypothesis test to compare three or more population proportions simultaneously

 

 

True

 

 

False

 

 

Question

 

 

14of40

 

 

All analyses of variance procedures require that the populations being compared have equal variances

 

 

True

 

 

False

 

 

Question

 

 

15of40

 

 

Analysis of variance compares the variance between samples to the variance within those samples to determine if means of populations differ

 

 

True

 

 

False

 

 

Question

 

 

16of40

 

 

The critical value for the Tukey-Kramer critical range is found using the F-distribution

 

 

True

 

 

False

 

 

Question

 

 

17of40

 

 

If the size for each sample is the same for the one-way ANOVA, the Tukey-Kramer critical range for all pairs would be the same

 

 

True

 

 

False

 

 

Question

 

 

18of40

 

 

The test statistics for one-way ANOVA follow the

 

 

normal distribution.

 

 

Student \\\'s t-distribution.

 

 

binomial distribution.

 

 

F-distribution.

 

 

Question

 

 

19of40

 

 

Consider the following partially completed one-way ANOVA summary table.

 

 

 

 

The degrees of freedom for the sum of squares between for this ANOVA procedure is

 

 

1.

 

 

2.

 

 

3.

 

 

4.

 

 

Question

 

 

20of40

 

 

The chi-square test for independence is used to decide if observed frequencies follow a known probability distribution

 

 

True

 

 

False

 

 

Question

 

 

21of40

 

 

When you reject the null hypothesis for a chi-square test of independence, you are concluding that no relationship exists between the two variables

 

 

True

 

 

False

 

 

Question

 

 

22of40

 

 

When performing a hypothesis test to compare two or more population proportions, the test statistic follows the ________.

 

 

normal distribution

 

 

Student\\\'s t-distribution

 

 

chi-square distribution

 

 

F-distribution

 

 

Question

 

 

23of40

 

 

The chi-square test requires that each expected frequency be equal to or greater than ________.

 

 

5

 

 

10

 

 

20

 

 

30

 

 

Question

 

 

24of40

 

 

Nationwide Insurance would like to perform a chi-square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated that they texted while driving. A random sample of 120 female teenagers found that 65 indicated that they texted while driving. The chi-square test statistic for this sample is ________.

 

 

1.36

 

 

2.98

 

 

4.05

 

 

4.22

 

 

Question

 

 

25of40

 

 

The Department of Transportation would like to investigate if differences exist in the proportions of flights that arrive on-time for Alaska Airlines, Delta Airlines, Southwest Airlines, and United Airlines. The following data represent the number of on-time flights from random samples taken from each airline.

 

 

 

 

The chi-square test statistic for these samples is ________.

 

 

2.60

 

 

4.65

 

 

6.22

 

 

8.37

 

 

Question

 

 

26of40

 

 

The test statistic used to compare the variances of two populations will always be greater than 1.0

 

 

True

 

 

False

 

 

Question

 

 

27of40

 

 

A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics exam has a standard deviation that is less than 5.0 minutes. The correct hypothesis statement would be ________.

 

 

H0:? ?5; H1:?< 5.

 

 

H0:?2?25; H1:?2 < 25.

 

 

H0:?2 = 5; H1:?2?5.

 

 

H0:?= 25; H1:? ?25.

 

 

Question

 

 

28of40

 

 

A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics exam has a standard deviation that is less than 5.0 minutes. A random sample of 15 students was selected, and the sample standard deviation for the time needed to complete the exam was found to be 4.0 minutes. The test statistic for this hypothesis test would be ________.

 

 

8.96

 

 

10.42

 

 

13.61

 

 

17.67

 

 

Question

 

 

29of40

 

 

A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics exam has a standard deviation that is less than 5.0 minutes. A random sample of 15 students was selected, and the sample standard deviation for the time needed to complete the exam was found to be 4.0 minutes. Using?= 0.05, the conclusion for this hypothesis test would be that because the test statistic is

 

 

more than the critical value, you fail to reject the null hypothesis and conclude that the standard deviation for the time to complete an exam is less than 5.0 minutes.

 

 

less than the critical value, you reject the null hypothesis and cannot conclude that the standard deviation for the time to complete an exam is less than 5.0 minutes.

 

 

less than the critical value, you fail to reject the null hypothesis and cannot conclude that the standard deviation for the time to complete an exam is less than 5.0 minutes.

 

 

more than the critical value, you fail to reject the null hypothesis and cannot conclude that the standard deviation for the time to complete an exam is less than 5.0 minutes.

 

 

Question

 

 

30of40

 

 

YouTube would like to test the hypothesis that the standard deviation for the length of an online video watched by a user is more than 2 minutes. A random sample of 21 people who watched online videos was selected. The sample standard deviation for the length of the video was found to be 2.5 minutes. The test statistic for this hypothesis test would be ________.

 

 

4.66

 

 

10.19

 

 

22.60

 

 

31.25

 

 

Question

 

 

31of40

 

 

YouTube would like to test the hypothesis that the standard deviation for the length of an online video watched by a user is more than 2 minutes. A random sample of 21 people who watched online videos was selected. The sample standard deviation for the length of the video was found to be 2.5 minutes. The degrees of freedom for this hypothesis test would be ________.

 

 

18

 

 

19

 

 

20

 

 

21

 

 

Question

 

 

32of40

 

 

Consider the relationship between the following variables:?Household income?Square footage of the primary residence Household income would be considered the independent variable

 

 

True

 

 

False

 

 

Question

 

 

33of40

 

 

Two variables have a correlation coefficient equal to -0.65 from a sample size of 10. Which of the following statements describes the results of a hypothesis test in which the population correlation coefficient is less than zero using?= 0.05?

 

 

Because the test statistic is less than the critical value, you can reject the null hypothesis and conclude that the population correlation coefficient is less than zero.

 

 

Because the test statistic is less than the critical value, you can reject the null hypothesis and conclude that the population correlation coefficient is not less than zero.

 

 

Because the test statistic is greater than the critical value, you can reject the null hypothesis and conclude that the population correlation coefficient is less than zero.

 

 

Because the test statistic is greater than the critical value, you fail to reject the null hypothesis, and you conclude that the population correlation coefficient is not less than zero.

 

 

Question

 

 

34of40

 

 

The ________ is used to test the significance of the population correlation coefficient.

 

 

normal distribution

 

 

Student\\\'s t-distribution

 

 

F-distribution

 

 

chi-square distribution

 

 

Question

 

 

35of40

 

 

The formula for the equation describing a straight line is = a + bx. The value for b in this equation represents the

 

 

predicted value of y given a value of x.

 

 

independent variable.

 

 

y-intercept of the straight line.

 

 

slope of the straight line.

 

 

Question

 

 

36of40

 

 

The ________ measures the variation in the dependent variable that is explained by variables other than the independent variable in simple regression analysis.

 

 

sum of squares within

 

 

sum of squares error

 

 

sum of squares regression

 

 

total sum of squares

 

 

Question

 

 

37of40

 

 

The table below shows the number of cars sold last month by six employees at Concord Motors and each employee\\\'s number of years of sales experience.

 

 

 

 

The correlation coefficient for this data is ________.

 

 

-0.251

 

 

0.460

 

 

0.655

 

 

0.844

 

 

Question

 

 

38of40

 

 

Costco sells paperback books in their retail stores and wanted to examine the relationship between price and demand. The price of a particular novel was adjusted each week, and the weekly sales were recorded in the table below.

 

 

 

 

Management would like to use simple regression analysis to estimate weekly demand for this novel using the price of the novel. The 95% prediction interval that estimates the weekly sales for a price of $9 is ________.

 

 

(2.37, 11.48)

 

 

(1.61, 12.24)

 

 

(1.26, 12.59)

 

 

(0.91, 12.94)

 

 

Question

 

 

39of40

 

 

105) ________ is present in the regression model when independent variables within the model are highly correlated.

 

 

Multicollinearity

 

 

Homoscedasticity

 

 

Correlation

 

 

Significance

 

 

Question

 

 

40of40

 

 

107) If the variance inflation factor exceeds ________, enough correlation exists between the independent variables to claim the presence of multicollinearity in the regression model.

 

 

3.0

 

 

5.0

 

 

6.0

 

 

10.0

 

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