A class has 420 students. The final examination is optional—taking it can raise, but cannot lower, a student’s grade. Of a random sample of 80 students, 31 indicated that they would take the final examination.
Find a 90% confidence interval for the t..
A clinic offers a weight-loss program. A review of its records found the following amounts of weight loss, in pounds, for a random sample of 10 clients at the conclusion of the program:
18.2 25.9 6.3 11.8 15.4 20.3 16.8 18.5 12.3 17.2 Find a 90% conf..
A clinic offers a weight-loss program. A review of its records found the following amounts of weight loss, in pounds, for a random sample of 24 of its clients at the conclusion of a 4-month program:
18 25 16 11 15 20 16 19
28 25 26 31 45 40 36 19
A coach recruits for a college team a star player who is currently a high school senior. In order to play next year, the senior must both complete high school with adequate grades and pass a standardized test. The coach estimates that the probability..
A college administers a student evaluation questionnaire for all its courses. For a random sample of 12 courses, the accompanying table and the data file Student Evaluation show both the average student ratings of the instructor (on a scale of 1 to 5..
A college admissions officer for an MBA program has determined that historically applicants have undergraduate grade point averages that are normally distributed with standard deviation 0.45. From a random sample of 25 applications from the current y..
A college basketball player who sinks 75% of her free throws comes to the line to shoot a “one and one” (if the first shot is successful, she is allowed a second shot, but no second shot is taken if the first is missed; one point is scored for each s..
A college bookseller makes calls at the offices of professors and forms the impression that professors are more likely to be away from their offices on Friday than any other working day. A review of the records of calls, 1/5 of which are on Fridays, ..
A college has 152 assistant professors, 127 associate professors, and 208 full professors. A journalist with the student newspaper was interested in whether faculty members were actually in their offices during posted office hours. The student journa..
A college has 152 assistant professors, 127 associate professors, and 208 full professors. The college administration is investigating the amount of time these faculty members spend in meetings in a semester. Random samples of 40 assistant professors..
A college has 3,200 undergraduate students and 800 graduate students. Researchers are interested in the amount of money spent in a year on textbooks by these students. Initially, simple random samples of 30 undergraduate students and 30 graduate stud..
A college’s economics department is attempting to determine if verbal or mathematical proficiency is more important for predicting academic success in the study of economics. The department faculty have decided to use the grade point average (GPA) i..
A committee of 8 members is to be formed from a group of 8 men and 8 women. If the choice of committee members is made randomly, what is the probability that precisely half of these members will be women?..
A company has 5 representatives covering large territories and 10 representatives covering smaller territories. The probability distributions for the numbers of orders received by each of these types of representatives in a day are shown in the accom..
A company has 50 sales representatives. It decides that the most successful representative during the previous year will be awarded a January vacation in Hawaii, while the second most successful will win a vacation in Las Vegas. The other representat..