Reference no: EM13472666

1.A hypothesis test gives a p-value of 0.30. If the significance level α = 0.05, the results are said to be

A) practically significant because the p-value > α.

B) statistically significant because the p-value > α.

C) not practically significant because the p-value > α.

D) not statistically significant because the p-value > α.

2.Suppose a 95% confidence interval for p, the proportion of drivers who admit that they sometimes run red lights when no one is around, is 0.29 to 0.38. Which of the following statements is false?

A) A test of Ho: ρ = 0.3 versus Ha: ρ ≠ 0.3 would not be rejected using a = 0.05.

B) It is plausible that a majority of all drivers would admit that they sometimes run red lights when no one is around.

C) A test of Ho: ρ = 0.5 versus Ha: ρ ≠ 0.5 would be rejected using a = 0.05.

D) It is plausible that about 37% of all drivers would admit that they sometimes run red lights when no one is around.

3.The primary purpose of a significance test is to

A) estimate the p-value of a sample.

B) decide whether there is enough evidence to support a research hypothesis, Ha, about a population.

C) decide whether there is enough evidence to support a research hypothesis, Ha, about a sample.

D) estimate the p-value of a population.

4.The primary purpose of a significance test is to

A) decide whether there is enough evidence to support a research hypothesis, Ha, about a sample.

B) decide whether there is enough evidence to support a research hypothesis, Ha, about a population.

C) estimate the p-value of a sample.

D) estimate the p-value of a population.

5.The p-value for a one-sided test for a mean was 0.04. The p-value for the corresponding two-sided test would be:

A) 0.04

B) 0.02

C) 0.08

D) 0.06

6.A researcher wants to assess if there is a difference in the average age of onset of a certain disease for men and women who get the disease. Let μ1 = average age of onset for women and μ2 = average age of onset for men. A random sample of 30 women with the disease showed an average age of onset of 83 years, with a sample standard deviation of 11.5 years. A random sample of 20 men with the disease showed an average age of onset of 77 years, with a sample standard deviation of 4.5 years. Assume that ages at onset of this disease are normally distributed for each gender, do not assume the population variances are equal. What are the appropriate null and alternative hypotheses?

A) μ1 = μ2 and Ha: μ1 > μ2

B) μ1 = μ2 and Ha: μ1 ≠ μ2

C) μ1 ≠ μ2 and Ha: μ1 = μ2

D) μ1 = μ2 and Ha: μ1 < μ2

7.In the survey of a random sample of students at a university, two questions were "How many hours per week do you usually study?" and "Have you smoked marijuana in the past six months?" An analysis of the results produced the above Minitab output. A research question of interest is whether students who have smoked marijuana (group 1) in the past 6 months study fewer hours on average per week than those who have not (group 2). What is the appropriate alternative hypothesis for this question?

A) x-bar1 - x-bar2 ≠ 0

B) μ1 - μ2 < 0

C) μ1 - μ2 = 0

D) x-bar1 - x-bar2 < 0

8.A shopper wanted to test whether there was a difference in the average waiting times at the check-out counter among 5 different supermarkets. She selected a random sample of 20 shoppers from each of the five supermarkets. What is the alternative hypothesis for this situation?

A) The average waiting time to check out is 25 minutes for all five supermarkets.

B) The average waiting time to check out is the same for all five supermarkets.

C) The average waiting time to check out is not the same for all five supermarkets.

D) The average waiting time for each of the 100 shoppers is different.

9.Ninety people with high cholesterol are randomly divided into three groups of thirty, and a different treatment program for decreasing cholesterol is assigned to each group. The response variable is the change in cholesterol level after two months of treatment. An analysis of variance will be used to compare the three treatments. What null hypothesis is tested by this ANOVA F-test?

A) The sample means are equal for the three treatment groups.

B) The sample variances are equal for the three treatment groups.

C) The population means are equal for the three treatments

D) The population variances are equal for the three treatments.

10.A study compared grade point averages (GPA) among students in 4 different majors (English, History, Statistics, and Art) using analysis of variance. A total sample size of 20 students (5 in each major) was studied. What are the numerator and denominator degrees of freedom for the ANOVA F-test?

A) 5 for numerator and 20 for denominator.

B) 3 for numerator and 16 for denominator.

C) 4 for numerator and 79 for denominator.

11.On a survey conducted at a university, students were asked how they felt about their weight (about right, overweight, or underweight), and also were asked to record their grade point average (GPA). There were 235 responses, with 160 saying their weight was about right, 50 said they were overweight, and 17 underweight. The question of interest is whether mean GPA is the same or differs for different weight attitude populations. Minitab output for the study is given above. The p-value of 0.008 is found by calculating:

A) the area to the right of 4.98 under an F-distribution with 2 and 234 degrees of freedom.

B) the area to the right of 4.98 under an F-distribution with 2 and 231 degrees of freedom.

C) the area to the right of 4.98 under an F-distribution with 2 and 232 degrees of freedom.

12.A study compared testosterone levels among athletes in four sports: soccer, track, Lacrosse, and water polo. The total sample size was n =30 (10 soccer, 10 track, 5 Lacrosse, and 5 water polo). A one-way analysis of variance was used to compare the population mean levels for the four sports. The sum of squared errors is SS Error = 100. What is the value of the Mean Square Error (MS Error)?

A) 3.45

B) 3.85

C) 10

13.Which of the following variables COULD be used in a Chi-Square analysis?

A) All of the above

B) Gender

C) Race

D) Age

E) Political Party Affiliation

F) Course Section Number

14.When conducting a chi-square test on two variables, a statistically significant relationship is illustrated when:

A) the sample produces a small relationship that is unlikely to have occurred even if there is no difference in the population.

B) the sample produces a small relationship that is likely to have occurred even if there is no difference in the population.

C) the sample produces a large relationship that is unlikely to have occurred even if there is no difference in the population.

D) the sample produces a large relationship that is likely to have occurred even if there is no difference in the population.

15.Which of the following is the BEST statement of the null hypothesis for conducting a Chi-Square analysis?

A) The variables ARE statistically related in the population

B) The variables are NOT statistically related in the population

C) The variables ARE statistically related in the sample

D) The variables are NOT statistically related in the sample

16.The table above shows the number of Olympic medals won by the three countries with the most medals during the 2000 Olympics in Sydney, Australia. There were a total of 244 medals won by the three countries. What percent of the medals won among the three countries were won by the USA?

A) 40.2%

B) 39.8%

C) 40.6%

D) 39.4%

17.The table above shows the counts by gender and highest degree attained for 498 respondents in the General Social Survey. What percent of the sample were males with no high school degree?

A) 48.5%

B) 9.8%

C) 22.6%

D) 20.3%

18.The table above shows the counts by gender and highest degree attained for 498 respondents in the General Social Survey. What percent of the sample did not graduate from high school?

A) 22.6%

B) 20.3%

C) 18.5%

D) 52.4%

19.The table above shows the responses from a sample of 680 people in the General Social Survey to the question, "Do you sometimes drink more than you think you should?" What is the risk (or percentage) of men thinking they drank more than they should?

A) 35.7%

B) 62.1%

C) 46.0%

D) 22.2%

20.A study on the use of seat belts versus belted booster seats for children ages 4 and 5 reported that "Using seat belts instead of booster seats was associated with increased risk for serious injury in an accident; the relative risk was 2.4." Based on this, it can be concluded that for this study:

A) The percent of children ages 4 and 5 wearing seatbelts was 2.4 times higher than the percent of children in a booster seat.

B) Children ages 4 and 5 wearing seatbelts were 2.4 times more likely to have serious injuries in an accident than were children in a booster seat.

C) The percent of children ages 4 and 5 in a booster seat was 2.4 times higher than the percent of children wearing seatbelts.

D) Children ages 4 and 5 in a booster seat were 2.4 times more likely to have serious injuries in an accident than were children wearing seatbelts

21.A survey asked people how often they exceed speed limits. The data are then categorized into the above contingency table of counts showing the relationship between age group and response. Among people with age over 30, what's the "risk" of always exceeding the speed limit?

A) 0.20

B) 0.40

C) 0.50

D) 0.33

22.The table above summarizes, by gender of respondent, the responses from 1,033 people to the question, "Do you smoke?" What is the odds ratio for women smoking (to not smoking) compared to men?

A) 0.91

B) 0.87

C) 1.15

D) 1.10

23.The table above shows the opinions of 1447 respondents in the General Social Survey to the question "Do you favor or oppose the death penalty for persons convicted of murder?" The purpose of examining the data is to see if there is a gender difference in how people would respond to this question. State the alternative hypotheses for this study.

A) There is a relationship in the sample between gender and opinion on the death penalty.

B) There is no relationship in the sample between gender and opinion on the death penalty.

C) There is a relationship in the population between gender and opinion on the death penalty.

D) There is no relationship in the population between gender and opinion on the death penalty.

24.The table above shows the opinions of 953 respondents in the General Social Survey to the question "Everything considered, would you say that in general, you approve or disapprove of wiretapping?" The purpose of examining the data is to see if there is a gender difference in how people would respond to this question. To test whether there is a relationship in the population between gender and support for wiretapping, the chi-square statistic = 11.7 and the p-value = 0.001. Are the results statistically significant or not statistically significant and what is the conclusion?

A) The results are not statistically significant. The conclusion is that there is not a relationship between gender and approving of the practice of wiretapping.

B) The results are not statistically significant. The conclusion is that there is a relationship between gender and approving of the practice of wiretapping.

C) The results are statistically significant. The conclusion is that there is not a relationship between gender and approving of the practice of wiretapping.

D) The results are statistically significant. The conclusion is that there is a relationship between gender and approving of the practice of wiretapping.

25.In a newspaper article about whether the regular use of Vitamin C reduces the risk of getting a cold, a researcher is quoted as saying that Vitamin C performed better than placebo in an experiment, but the difference was not larger than what could be explained by chance. In statistical terms, the researcher is saying the results are _______

A) due to non-sampling errors.

B) definitely due to chance.

C) statistically significant.

D) not statistically significant.