GBS 221 Business Statistics Final Exam Part 1

Question1of40If 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 attentionTrueFalseQuestion2of40A 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 existTrueFalseQuestion3of40CoStar 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 beH0: π ≤ 0.08; H1: π > 0.08. H0: π = 0.08; H1: π < 0.08. H0: π = 0.08; H1: π ≠ 0.08. H0: π ≠ 0.08; H1: π = 0.08Question4of40CoStar 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 wasmore 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%.Question5of40The p-value for a hypothesis test is defined as the probability of observing acritical 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.Question6of40The 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±1.6451.645±1.96Question7of40Sony 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±1.962.33Question8of40Sony 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= -2.17Question9of40The 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= -2.23Question10of40Two 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)Question11of40The 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)Question12of40The 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.American     21    17    17    20    25    16    20    16French     24    18    20    28    18    29    17    

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.Question13of40Analysis of variance is a technique used to conduct a hypothesis test to compare three or more population proportions simultaneouslyTrueFalseQuestion14of40All analyses of variance procedures require that the populations being compared have equal variancesTrueFalseQuestion15of40Analysis of variance compares the variance between samples to the variance within those samples to determine if means of populations differTrueFalseQuestion16of40The critical value for the Tukey-Kramer critical range is found using the F-distributionTrueFalseQuestion17of40If the size for each sample is the same for the one-way ANOVA, the Tukey-Kramer critical range for all pairs would be the sameTrueFalseQuestion18of40The test statistics for one-way ANOVA follow thenormal distribution.Student 's t-distribution.binomial distribution.F-distribution.Question19of40Consider the following partially completed one-way ANOVA summary table. The degrees of freedom for the sum of squares between for this ANOVA procedure is1.2.3.4.Question20of40The chi-square test for independence is used to decide if observed frequencies follow a known probability distributionTrueFalseQuestion21of40When you reject the null hypothesis for a chi-square test of independence, you are concluding that no relationship exists between the two variablesTrueFalseQuestion22of40When performing a hypothesis test to compare two or more population proportions, the test statistic follows the ________.normal distributionStudent's t-distributionchi-square distributionF-distributionQuestion23of40The chi-square test requires that each expected frequency be equal to or greater than ________.5102030Question24of40Nationwide 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 ________.1.362.984.054.22Question25of40The 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.    Alaska    Delta    Southwest    United Number On-time    90    95    85    60Sample size    100    120    100    80

The chi-square test statistic for these samples is ________.2.604.656.228.37Question26of40The test statistic used to compare the variances of two populations will always be greater than 1.0TrueFalseQuestion27of40A 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:μ ≥ 5; H1:μ < 5H0:σ2≥ 25; H1:σ2 < 25H0: σ2 = 5; H1: σ2≠ 5H0: σ = 25; H1: ≠ σ25.Question28of40A 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 ________.8.9610.4213.6117.67Question29of40A 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 ismore 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.Question30of40YouTube 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 ________.4.6610.1922.6031.25Question31of40YouTube 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 ________.18192021Question32of40Consider the relationship between the following variables:? Household income? Square footage of the primary residence Household income would be considered the independent variableTrueFalseQuestion33of40Two 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.Question34of40The ________ is used to test the significance of the population correlation coefficient.normal distributionStudent's t-distributionF-distributionchi-square distributionQuestion35of40The formula for the equation describing a straight line is = a + bx. The value for b in this equation represents thepredicted value of y given a value of x.independent variable.y-intercept of the straight line.slope of the straight line.Question36of40The ________ measures the variation in the dependent variable that is explained by variables other than the independent variable in simple regression analysis.sum of squares withinsum of squares errorsum of squares regressiontotal sum of squaresQuestion37of40The 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. Experience     Sales 1    72    92    94    85    148    14

The correlation coefficient for this data is ________.-0.2510.4600.6550.844Question38of40Costco 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)Question39of40105) ________ is present in the regression model when independent variables within the model are highly correlated.MulticollinearityHomoscedasticityCorrelationSignificanceQuestion40of40107) If the variance inflation factor exceeds ________, enough correlation exists between the independent variables to claim the presence of multicollinearity in the regression model.3.05.06.010.0