Questions and Answers Archive - Page 10 of 85

For which of the following is a chi-square goodness-of-fit test most appropriate? A) Estimating a difference between two population means B) Estimating a difference between two population proportions C) Finding the expected value of a probability distribution D) Determining whether a categorical variable has a significantly different distribution of proportions than the expected distribution E) Determining the best shape for a set of data

For which of the following is a chi-square goodness-of-fit test most appropriate? A) Estimating a difference between two population means B) Estimating a difference between two population proportions C) Finding the expected value of a probability distribution D) Determining whether a categorical variable has a significantly different distribution of proportions than the expected distribution E) … Read more

An administrator at a local high school wants to investigate whether there is an association between the grade level of a student (either ninth, tenth, eleventh, or twelfth) and how the student commutes to school (either walks, bikes, takes the bus, receives a ride, or drives). After a chi-square test for association was conducted, the results indicated that the chi-square test statistic was 14.63 with a p-value of 0.2623. Which of the following is the correct interpretation of the p-value in the context of the test? A) There is a 26.23 percent chance that grade level and how a student commutes to school are independent. B) There is a 26.23 percent chance that there is no association between grade level and how a student commutes to school. C) Assuming there is no association between a student’s grade level and how the student commutes to school, there is a 26.23 percent chance of finding a test statistic that is 14.63 or larger. D) Assuming that a student’s grade level and the way the student commutes to school are dependent, there is a 26.23 percent chance of finding a test statistic that is 14.63 or larger. E) Assuming that a student’s grade level and the way the student commutes to school are dependent, there is a 26.23 percent chance of finding a test statistic that is 14.63 or smaller.

An administrator at a local high school wants to investigate whether there is an association between the grade level of a student (either ninth, tenth, eleventh, or twelfth) and how the student commutes to school (either walks, bikes, takes the bus, receives a ride, or drives). After a chi-square test for association was conducted, the … Read more

Which of the following is not a condition for a chi-square goodness-of-fit test? A) Data should be collected using a random sample or randomized experiment. B) When sampling without replacement, the sample size cannot be greater than 10 percent of the population size. C) All expected counts should be greater than 5. D) The distribution of the sample should be approximately normal. E) During the sampling process, each individual chosen should be independent of the next

Which of the following is not a condition for a chi-square goodness-of-fit test? A) Data should be collected using a random sample or randomized experiment. B) When sampling without replacement, the sample size cannot be greater than 10 percent of the population size. C) All expected counts should be greater than 5. D) The distribution … Read more

The biologist found evidence to reject the null hypothesis in favor of the alternative hypothesis. Which of the following represents the alternative hypothesis of the test? A) At least one of the fish proportions is different than the corresponding proportion when the lake was originally stocked. B) The proportions for the different fish types are the same as the corresponding proportions when the lake was originally stocked. C) The proportions are evenly distributed among fish types. D) At least one of the fish proportions is the same as the corresponding proportion when the lake was stocked. E) All of the fish proportions are different than the corresponding proportions when the lake was stocked.

The biologist found evidence to reject the null hypothesis in favor of the alternative hypothesis. Which of the following represents the alternative hypothesis of the test? A) At least one of the fish proportions is different than the corresponding proportion when the lake was originally stocked. B) The proportions for the different fish types are … Read more

If the proportions of nests occupied is the same for golf and nongolf sites, what would be the expected count of birdhouses with 1 nest in nongolf locations? A) 40 B) 42 C) 50 D) 58 E) 60

In order to meet the conditions for independence and large counts for a chi-square goodness-of-fit test, which of the following represents all possible sizes of the monthly samples? A) n≥30 B) 30≤n≤50 C) 46≤n≤60 D) n≥46 E) n≤60

In order to meet the conditions for independence and large counts for a chi-square goodness-of-fit test, which of the following represents all possible sizes of the monthly samples? A) n≥30 B) 30≤n≤50 C) 46≤n≤60 D) n≥46 E) n≤60

Assuming that all conditions for inference have been met, which of the following equations gives the appropriate chi-square test statistic and the correct number of degrees of freedom to determine if there is an association between grade level and whether a student approves of the food choices in the cafeteria? A) χ2=(50−40)240+(20−40)240+(30−40)240+(60−40)240 with 4 degrees of freedom B) χ2=(50−35)250+(20−35)220+(30−45)230+(60−45)260 with 4 degrees of freedom C) χ2=(50−35)235+(20−35)235+(30−45)245+(60−45)245 with 4 degrees of freedom D) χ2=(50−40)240+(20−40)240+(30−40)240+(60−40)240 with 1 degree of freedom E) χ2=(50−35)235+(20−35)235+(30−45)245+(60−45)245 with 1 degree of freedom

Assuming that all conditions for inference have been met, which of the following equations gives the appropriate chi-square test statistic and the correct number of degrees of freedom to determine if there is an association between grade level and whether a student approves of the food choices in the cafeteria? A) χ2=(50−40)240+(20−40)240+(30−40)240+(60−40)240 with 4 degrees … Read more

A local restaurant claims that it gets 45 percent of its customers from Monday through Thursday, 20 percent on Friday, 20 percent on Saturday, and 15 percent on Sunday. How many degrees of freedom should be used to conduct a chi-square goodness-of-fit test of the claim? A) 3 B) 4 C) 6 D) 7 E) It is not possible to determine the degrees of freedom without knowing the sample size.

A local restaurant claims that it gets 45 percent of its customers from Monday through Thursday, 20 percent on Friday, 20 percent on Saturday, and 15 percent on Sunday. How many degrees of freedom should be used to conduct a chi-square goodness-of-fit test of the claim? A) 3 B) 4 C) 6 D) 7 E) … Read more

The district manager of four different restaurants wanted to investigate whether the four restaurants differed with respect to customers ordering dessert or not based on family classification (with children or without children). Independent random samples of 100 customers who ordered dessert were selected from each restaurant, and the customers were identified as either being with children or without children. After verifying the conditions for the appropriate hypothesis test, the manager calculated a chi-square test statistic of 6.45 with an associated p-value of 0.092. Based on the p-value and α=0.05, what conclusion should the manager make regarding the proportion of customers who order dessert at each restaurant and the customers’ family classification? A) There is convincing statistical evidence to suggest that the proportion of customers who order dessert at each restaurant is the same based on family classification. B) There is convincing statistical evidence to suggest that the proportion of customers who order dessert at each restaurant is not the same based on family classification. C) There is not convincing statistical evidence to prove that the proportion of customers who order dessert at each restaurant is not the same based on family classification. D) There is not convincing statistical evidence to suggest that the proportion of customers who order dessert at each restaurant is the same based on family classification. E) There is not convincing statistical evidence to suggest that the proportion of customers who order dessert at each restaurant is not the same based on family classification.

The district manager of four different restaurants wanted to investigate whether the four restaurants differed with respect to customers ordering dessert or not based on family classification (with children or without children). Independent random samples of 100 customers who ordered dessert were selected from each restaurant, and the customers were identified as either being with … Read more

Polling organizations regularly collect data on the public’s opinions and habits. A question on a recent survey asked, “How often do you purchase coffee from a coffeehouse?” There may be differences in how people respond to this question based on whether the person is a full-time student. Suppose a polling organization uses random digit dialing of local phone numbers to take a poll and asks respondents whether they are full-time students. In addition, they ask respondents to identify how often they purchase coffee from a coffeehouse (never, once a week, two to three times a week, daily, more than once a day). The data are collected in a 5-by-2 table of counts. Which of the following is the appropriate null hypothesis when conducting a chi-square test for the data? A) H0 : The proportion of people for each category in the 5-by-2 table will be 10 percent. B) H0 : For each purchasing frequency, the proportion of full-time students is different. C) H0 : How often a person purchases coffee from a coffeehouse is not associated with whether a person is a full-time student. D) H0 : How often a person purchases coffee from a coffeehouse is dependent on whether a person is a full-time student. E) H0 : There is an association between how often a person purchases coffee from a coffeehouse and whether a person is a full-time student.

Polling organizations regularly collect data on the public’s opinions and habits. A question on a recent survey asked, “How often do you purchase coffee from a coffeehouse?” There may be differences in how people respond to this question based on whether the person is a full-time student. Suppose a polling organization uses random digit dialing … Read more