BNAL 306 test 1 quizzes
A statistics professor wanted to test whether the grades on a statistics test were the same for upper and lower classmen. The professor took a random sample of size 10 from each, conducted a test and found out that the variances were equal. For this situation, the professor should use a t test with related samples. True False
False
A test for whether one proportion is higher than the other can be performed using the chi-square distribution. True False
False
If you are comparing the mean sales among 3 different brands you are dealing with a three-way ANOVA design. True False
False
In a hypothesis test, it is irrelevant whether the test is a one-tail or two-tail test. True False
False
Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.034. The null hypothesis should be rejected if the chosen level of significance is 0.01. True False
False
The larger the p-value, the more likely you are to reject the null hypothesis. True False
False
The sample size in each independent sample must be the same if we are to test for differences between the means of two independent populations. True False
False
The squared difference between the observed and theoretical frequencies should be large if there is no significant difference between the proportions. True False
False
A researcher is curious about the effect of sleep on students' test performances. He chooses 60 students and gives each two tests: one given after two hours' sleep and one after eight hours' sleep. The test the researcher should use would be a related samples test. True False
True
In a one-factor ANOVA analysis, the among sum of squares and within sum of squares must add up to the total sum of squares. True False
True
Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.043. The null hypothesis should be rejected if the chosen level of significance is 0.05. True False
True
Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.043. The null hypothesis should be rejected if the chosen level of significance is 0.05. True False
True
The director of admissions at a state college is interested in seeing if admissions status (admitted, waiting list, denied admission) at his college is independent of the type of community in which an applicant resides. He takes a sample of recent admissions decisions and forms the following table: He will use this table to do a chi-square test of independence with a level of significance of 0.01. Referring to Table 12-11, the alternative hypothesis claims that "there is some connection between admission status at the college and the type of community in which an applicant resides." True False
True
The smaller the p-value, the stronger is the evidence against the null hypothesis. True False
True
The statement of the null hypothesis always contains an equality. True False
True
A real estate company is interested in testing whether the mean time that families in Gotham have been living in their current homes is less than families in Metropolis. Assume that the two population variances are equal. A random sample of 100 families from Gotham and a random sample of 150 families in Metropolis yield the following data on length of residence in current homes. Referring to Table 10-3, which of the following represents the relevant hypotheses tested by the real estate company? a. H0:μG - M≥0 versus H1:μG - M < 0 b. H0:μG - M≤0 versus H1:μG - M > 0 c. H0:μG - M = 0 versus H1:μG - M≠0 d. H0 :x̄G - M≥0 versus H1 :x̄G - M < 0
a
Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below. Referring to Table 10-1, find the p-value if we assume that the alternative hypothesis was a two-tail test. a. Smaller than 0.01 b. Between 0.01 and 0.05 c. Between 0.05 and 0.10 d. Greater than 0.10
a
In a one-way ANOVA, the null hypothesis is always a. there is no difference in the population means. b. there is some treatment effect. c. all the population means are different. d. some of the population means are different.
a
Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below. Referring to Table 10-1, give the null and alternative hypotheses to determine if the mean SSATL score of Japanese managers differs from the mean SSATL score of American managers. a. H0: A - J≥0 versus H1: A - J < 0 b. H0: A - J ≤ 0 versus H1: A - J > 0 c. H0: A - J = 0 versus H1: A - J ≠0 d. H0 : A - J = 0 versus H1: A - J≠0
c.
The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01 what conclusion can she make? a. There is not sufficient evidence that the mean age of her customers is greater than 30. b. There is sufficient evidence that the mean age of her customers is greater than 30. c. There is not sufficient evidence that the mean age of her customers is not greater than 30. d. There is sufficient evidence that the mean age of her customers is not greater than 30.
a
A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of 5 memory locations. A check at the end of a day's transactions gave the counts shown in the table to each of the 5 memory locations, along with the number of reported errors. Memory Location 1 2 3 4 5 Number of Reported Errors 11 12 6 9 10 Number of Correct Transactions 71 88 68 83 92 The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the 5 memory locations differ. Referring to Table 12-4, which test would be used to properly analyze the data in this experiment? a. X2 test of independence b. X2 test for difference among more than two proportions c. McNemar test for the difference between two proportions d. McNemar test for the difference among more than two proportions
b
An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps as few passengers as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) The number of passengers bumped each week is obtained, which gives rise to the following output: Referring to Table 11-1, the among-group (between-group) mean squares is a. 8.525. b. 70.8. c. 212.4. d. 637.2.
b
An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps the fewest mean number of passengers as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) The number of passengers bumped each week is given below. How should the data be analyzed? Package 1: 12, 14, 9, 11, 16 Package 2: 2, 4, 7, 3, 1 Package 3: 10, 9, 6, 10, 12 Package 4: 7, 6, 6, 15, 12 a. F test for differences in variances b. One-way ANOVA F test c. t test for the differences in means d. t test for the mean difference
b
Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below. Referring to Table 10-1, judging from the way the data were collected, which test would likely be most appropriate to employ? a. Paired t test b. Pooled-variance t test for the difference between two means c. F test for the ratio of two variances d. Z test for the difference between two proportions
b
Are Japanese managers more motivated than American managers? A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below. Referring to Table 10-1, what is the value of the test statistic? Selected Answer: a. -14.08 b. -11.8092 c. -1.9677 d. 96.4471
b
If an economist wishes to determine whether there is evidence that mean family income in a community exceeds $50,000 a. either a one-tail or two-tail test could be used with equivalent results. b. a one-tail test should be utilized. c. a two-tail test should be utilized. d. None of these.
b
If the p-value is less than in a two-tail test, a. he null hypothesis should not be rejected. b. the null hypothesis should be rejected. c. a one-tail test should be used. d. no conclusion should be reached.
b
In a one-way ANOVA, if the computed F statistic is greater than the critical F value you may a. reject H0 since there is evidence all the means differ. b. reject H0 since there is evidence that not all the means are the same. c. not reject H0 since there is no evidence of a difference in the means. d. not reject H0 because a mistake has been made.
b
In testing for differences between the means of two independent populations, the null hypothesis is a. H0: 1 - 2 = 2. b. H0: 1 - 2 = 0. c. H0: 1 - 2 > 0. d. H0: 1 - 2 < 2.
b
In testing for differences between the means of two related populations, the null hypothesis is a. H0: D = 2. b. H0: D = 0. c. H0: D < 0. d. H0: D > 0.
b
In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves? a. A test for the equality of variances from 2 independent populations b. A test for the difference between the means of 2 related populations c. A test for the difference between the means of 2 independent populations d. All of these.
b
The Wall Street Journal recently published an article indicating differences in perception of sexual harassment on the job between men and women. The article claimed that women perceived the problem to be much more prevalent than did men. One question asked of both men and women was: "Do you think sexual harassment is a major problem in the American workplace?" 24% of the men compared to 62% of the women responded "Yes." Assuming W designates women's responses and M designates men's, what hypothesis should The Wall Street Journal test in order to show that its claim is true? a. H0: W - M ≥0 versus H1: W - M < 0 b. H0: W - M ≤0 versus H1: W - M > 0 c. H0: W - M = 0 versus H1: W - M ≠0 d. H0: W - M≠ 0 versus H1: W - M = 0
b
The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are: a. H0: μ ≥ 30 versus H1:μ < 30. b. H0: μ ≤ 30 versus H1: μ > 30. c. H0: X ≥ 30 versus H1: X < 30. d. H0: X ≤ 30 versus H1: X > 30.
b
The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. What is the p-value associated with the test statistic? a. 0.3577 b. 0.1423 c. 0.0780 d. 0.02
c
The t test for the difference between the means of 2 independent populations assumes that the respective a. sample sizes are equal. b. sample variances are equal. c. populations are approximately normal. d. All of these.
c
A ________ is a numerical quantity computed from the data of a sample and is used in reaching a decision on whether or not to reject the null hypothesis. a. significance level b. critical value c. test statistic d. parameter
c
An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps as few passengers as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) The number of passengers bumped each week is obtained, which gives rise to the following output: Referring to Table 11-1, at a significance level of 1%, a. there is insufficient evidence to conclude that the mean number of customers bumped by the 4 packages are not all the same. b. there is insufficient evidence to conclude that the mean number of customers bumped by the 4 packages are all the same. c. there is sufficient evidence to conclude that the mean number of customers bumped by the 4 packages are not all the same. d. there is sufficient evidence to conclude that the mean number of customers bumped by the 4 packages are all the same.
c
An airline wants to select a computer software package for its reservation system. Four software packages (1, 2, 3, and 4) are commercially available. The airline will choose the package that bumps as few passengers as possible during a month. An experiment is set up in which each package is used to make reservations for 5 randomly selected weeks. (A total of 20 weeks was included in the experiment.) The number of passengers bumped each week is obtained, which gives rise to the following output: Referring to Table 11-1, the within groups degrees of freedom is a. 3. b. 4. c. 16. d. 19.
c
If an economist wishes to determine whether there is evidence that mean family income in a community equals $50,000 a. either a one-tail or two-tail test could be used with equivalent results. b. a one-tail test should be utilized. c. a two-tail test should be utilized. d. None of these.
c
If we wish to determine whether there is evidence that the proportion of items of interest is the same in group 1 as in group 2, the appropriate test to use is a. the Z test. b. the X2 test. c. Both the Z test and the X2 test. d. Neither the Z test nor the X2 test.
c
Recent studies have found that American children are more obese than in the past. The amount of time children spent watching television has received much of the blame. A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television. We are interested in testing whether the mean number of hours spent watching TV and weights are independent at 1% level of significance. Referring to Table 12-13, if there is no connection between weights and average number of hours spent watching TV, we should expect how many children to be spending more than 6 hours on average watching TV and are more than 10 lbs. underweight? a. 5.8 b. 6.2 c. 8 d. 12
c
The F test statistic in a one-way ANOVA is a. MSW/MSA. b. SSW/SSA. c. MSA/MSW. d. SSA/SSW.
c
The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to have a level of significance at 0.01, what decision should she make? a. Reject H0. b. Reject H1. c. Do not reject H0. d. We cannot tell what her decision should be from the information given.
c
A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. In order to determine if his suspicion is correct, he contacts a second supplier and asks for the prices on various identical materials. He wants to compare these prices with those of his primary supplier. The data collected is presented in the table below, with some summary statistics presented (all of these might not be necessary to answer the questions which follow). The buyer believes that the differences are normally distributed and will use this sample to perform an appropriate test at a level of significance of 0.01. a. pooled-variance t test for differences between two means. b. separate-variance t test for differences between two means. c. Z test for the difference between two proportions. d. paired t test for the mean difference.
d
A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of 5 memory locations. A check at the end of a day's transactions gave the counts shown in the table to each of the 5 memory locations, along with the number of reported errors. Memory Location 1 2 3 4 5 Number of Reported Errors 11 12 6 9 10 Number of Correct Transactions 71 88 68 83 92 The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the 5 memory locations differ. Referring to Table 12-4, at 1% level of significance a. there is sufficient evidence to conclude that the proportions of errors in transactions assigned to each of the 5 memory locations are all different. b. there is insufficient evidence to conclude that the proportions of errors in transactions assigned to each of the 5 memory locations are all different. c. there is sufficient evidence to conclude that the proportion of errors in transactions assigned to each of the 5 memory locations are not all the same. d. there is insufficient evidence to conclude that the proportion of errors in transactions assigned to each of the 5 memory locations are not all the same.
d
A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of 5 memory locations. A check at the end of a day's transactions gave the counts shown in the table to each of the 5 memory locations, along with the number of reported errors. Memory Location 1 2 3 4 5 Number of Reported Errors 11 12 6 9 10 Number of Correct Transactions 71 88 68 83 92 The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the 5 memory locations differ. Referring to Table 12-4, the calculated value of the test statistic is a. -0.1777. b. -0.0185. c. 1.207 d. 1.500.
d
Moving companies are required by the government to publish a Carrier Performance Report each year. One of the descriptive statistics they must include is the annual percentage of shipments on which a $50 or greater claim for loss or damage was filed. Suppose two companies, Econo-Move and On-the-Move, each decide to estimate this figure by sampling their records, and they report the data shown in the following table. The owner of On-the-Move is hoping to use these data to show that the company is superior to Econo-Move with regard to the percentage of claims filed. Which test would be used to properly analyze the data in this experiment? a. t test for the difference between two means b. F test for the difference between two variances c. Separate variance t test for the difference between two means d. Z test for the difference between two proportions
d
Recent studies have found that American children are more obese than in the past. The amount of time children spent watching television has received much of the blame. A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television. We are interested in testing whether the mean number of hours spent watching TV and weights are independent at 1% level of significance. Referring to Table 12-13, suppose the value of the test statistic was 30.00 (which is not the correct value) and the critical value at 1% level of significance was 10.00 (which is not the correct value), which of the following conclusions would be correct? a. We will not reject the null and conclude that mean number of hours spent watching TV and weights are independent. b. We will reject the null and conclude that mean number of hours spent watching TV and weights are independent. c. We will not reject the null and conclude that mean number of hours spent watching TV and weights are not independent. d. We will reject the null and conclude that mean number of hours spent watching TV and weights are not independent.
d
When would you use the Tukey-Kramer procedure? a. To test for normality b. To test for homogeneity of variance c. To test independence of errors d. To test for differences in pairs of means
d