There are four questions about this problem in the test shown in random order. Out of 1000 customers in the test data, there are only 100 buyers. A classification model applied to these customers, predicts 200 buyers. If buying is regarded as positive, there are 50 true positives. What is precision? O a. 10% O b. 25% O c. 20% O d. 50%

State whether each situation has independent or paired (dependent) samples. a. A researcher wants to compare the salaries of men and women. She finds a random sample of 80 men and 80 women, and measures their salaries. b. A researcher wants to know whether professors with tenure have fewer office hours than professors without tenure. She observes the number of office hours for professors with and without tenure. a. Choose the correct answer below. O Independent samples O Paired (dependent) samples b. Choose the correct answer below. O Independent samples Paired (dependent) samples

A researcher wants to determine if the number of years of education for a parent correlates with the number of years of education for their child. The table shows the number of years of education of the parent and the number of years of education of their child for a random sample of 7.    Years of Education of Parent: 13, 9, 12, 10, 12, 10, 12 Years of Education of their Child: 15, 11, 10, 16, 17, 12, 17   Conduct a hypothesis test to determine if there is a significant linear correlation between the two variables. Use α = 0.05. If there is a significant linear correlation between the variables, determine the regression equation.  There is a significant correlation between the variables and the regression equation is y' = 5.333 + 0.777x  There is a significant correlation between the variables and the regression equation is y' = 0.777 + 5.333x  There is not a significant correlation between the variables, so the regression equation should not be determined.  There is a significant…

A survey is conducted to determine if there is a Because the P-value of this test is large, there is not convincing evidence that the distribution of responses for the population of all students, parents, and teachers of this large high school differs. For which categories are the observed counts greater than expected? difference in the proportion of students, parents, and teachers who volunteer at least once a month. To investigate, a random sample of 45 students, 25 parents, and 12 teachers was selected from a large high school. The data are displayed in the tables. Observed counts: O There were more students than expected who do Student Parent Teacher Yes No not volunteer, and more parents and teachers than expected who do volunteer. 24 12 6 Volunteer? 21 13 6 There were more students than expected who do volunteer, and more parents and teachers than expected who do not volunteer. Expected counts: There were more teachers than expected who do Student Parent Teacher not volunteer,…

Treat the dataset as your bag of peanut M&M’s (a simple random sample). Count the number of orange M&M’s and the total number of M&M’s in your bag. Then determine the proportion of your M&M’s that are orange. Number of orange M&M’s: 13 Total number of M&M’s: 65 Proportion of orange M&M’s: 0.2   Question below is according to this.

How many samples or treatments are here?   490 undergraduate students at a state university in the southwestern region of the United States were surveyed. Each student in the sample was classified according to class standing (freshman, sophomore, junior, or senior) and body are category (body piercings only, tattoos only, both tattoos and body piercings, no body art). Use the data in the accompanying table to determine if there is an association between class standing and body art category. Assume that it is reasonable to regard the sample as representative of the students at this university. Use α = 0.01.                                                             Freshman  Sophmore   Junior    Senior Body Piercings                                          61              7              14          86 Only Tattoos                                             43              11             10         64 Only Mildly Piercings and Tattoos            20                9              7…

Suppose a survey of 931 business owners found that 23% bought flood insurance. Which part of the survey represents the descriptive branch of statistics? Make an inference based on the results of the survey. Choose the best statement of the descriptive statistic in the problem. O A. Most business owners do not buy flood insurance. B. There is no association between business owners and buying flood insurance. OC. 931 business owners were surveyed. O D. 23% of business owners in the sample bought flood insurance. Choose the best inference from the given information. OA. 23% of business owners in the sample bought flood insurance. OB. 931 business owners were surveyed. OC. Most business owners do not buy flood insurance. D. There is no association between business owners and buying flood insurance.

A television station wishes to study the relationship between viewership of its 11 p.m. news program and viewer age (18 years or less, 19 to 35, 36 to 54, 55 or older). A sample of 250 television viewers in each age group is randomly selected, and the number who watch the station’s 11 p.m. news is found for each sample. The results are given in the table below.      Age Group     Watch11 p.m. News? 18 or less 19 to 35 36 to 54 55 or Older Total Yes 37 46 59 83 225 No 213 204 191 167 775 Total 250 250 250 250 1,000     (a) Let p1, p2, p3, and p4 be the proportions of all viewers in each age group who watch the station’s 11 p.m. news. If these proportions are equal, then whether a viewer watches the station’s 11 p.m. news is independent of the viewer’s age group. Therefore, we can test the null hypothesis H0 that p1, p2, p3, and p4 are equal by carrying out a chi-square test for independence. Perform this test by setting α = .05. (Round your answer to 3 decimal places.)…

The General Social Survey is an annual survey given to a random selection of about 1500 adults in the United States. Among the many questions asked are "What is the highest level of education you've completed?" and "If you're employed full-time, how many hours do you spend working at your job during a typical week?" In a recent year, 1079 respondents answered both questions. The summary statistics are given in the chart below. (The sample data consist of the times, in hours per week, that were given by the respondents.) Sample Sample Sample size Groups mean variance Less than h.s. High school Bachelor's 258 40.9 101.8 263 41.8 97.5 270 42.2 94.4 Graduate 288 43.0 98.7 Send data to calculator Send data to Excel To decide if there are any differences in the mean hours per week worked by these different groups, we can perform a one-way, independent-samples ANOVA test. Such a test uses the following statistic. Variation between the samples F= Variation within the samples For the data from…

A television station wishes to study the relationship between viewership of its 11 p.m. news program and viewer age (18 years or less, 19 to 35, 36 to 54, 55 or older). A sample of 250 television viewers in each age group is randomly selected, and the number who watch the station’s 11 p.m. news is found for each sample. The results are given in the table below.      Age Group     Watch11 p.m. News? 18 or less 19 to 35 36 to 54 55 or Older Total Yes 49 59 61 84 253 No 201 191 189 166 747 Total 250 250 250 250 1,000     (a) Let p1, p2, p3, and p4 be the proportions of all viewers in each age group who watch the station’s 11 p.m. news. If these proportions are equal, then whether a viewer watches the station’s 11 p.m. news is independent of the viewer’s age group. Therefore, we can test the null hypothesis H0 that p1, p2, p3, and p4 are equal by carrying out a chi-square test for independence. Perform this test by setting α = .05. (Round your answer to 3 decimal places.)…