The management of a company finds that 27% of the administrative assistants hired are unsatisfactory. The personnel director is instructed to devise a test that will improve the situation. 100 employed administrative assistants are chosen at random and are given the newly constructed test. Out of these, 73% of the satisfactory administrative assistants pass the test and 37% of the unsatisfactory administrative assistants pass. Based on these results, if a person applies for a job, takes the test, and passes it, what is the probability that he or she is a satisfactory administrative assistant? If the applicant fails the test, what is the probability that he or she is a satisfactory administrative assistant?

Among students at a nearby college, the proportion who say they’re interested in their congressional district’s election results has traditionally been 70%. After a series of lackluster debates on campus, a political scientist claims that the proportion, p, of students at the college who say they’re interested in their districts election results is now less than 70%. A pill is commissioned, and 154 out of random sample of 230 students at the college say they’re interested in their districts election results. Is there enough evidence to support the political scientist’s claim at the 0.05 level of significance? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table.

A fitness course claims that it can improve an individual's physical ability. To test the effect of a physical fitness course on one's physical ability, the number of sit-ups that a person could do in one minute, both before and after the course, was recorded. Ten individuals are randomly selected to participate in the course. The results are displayed in the following table. Can it be concluded, from the data, that participation in the physical fitness course resulted in significant improvement? Let d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course)d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course). Use a significance level of α=0.05α=0.05 for the test. Assume that the numbers of sit-ups are normally distributed for the population both before and after taking the fitness course. Sit-ups before 3232 4545 2121 5050 3636 4444 2626 2020…

In a study about learning styles, researchers used a group of 64 elementary school students who volunteered to be part of the study. The researchers gave each student a pre-test and based upon the results, they divided them into 32 pairs of similarly scoring students. School administrators then randomly assigned one student from each pair to mathematics instruction online while the other student received in-person instruction in a traditional classroom. At the end of the year, all 64 students received a mathematics assessment, measured on a 100-point scale.   The researchers calculated the difference (in person −− online) in the mathematics assessment scores for each pair of students. The 32 differences had a mean of 15 and a standard deviation of 3.9 points.   Construct and interpret a 95% confidence interval for the mean difference (in person −− online) in the mathematics assessment scores for all pairs of students like these who learn math either face-to-face or online.