A local company is concerned about the number of days missed by its employees due to illness. A random sample of 10 employees is selected. The number of days absent in one year is listed below. An incentive program is offered in an attempt to decrease the number of days absent. The number of days absent in one year after the incentive program is listed below. Employee A BC DEF GHIJ Days Absent Before the 2 0 13 2 6 14 7 4 8 8 Incentive Days Absent After the 4 6 2 2 4 0 o 9 0 6 Incentive Find the mean difference ud 3.1

In a US presidential election, the incumbent president wins with 51.5% of the vote to 48.2% for the primary challenger (and .3% to others). In a nationwide telephone poll of 1000 people conducted exactly one week before the election by a university polling group, 49% of people polled supported the incumbent president, 50% supported the challenger, and 1% supported other candidates. a. For the polling study, what was the population of interest? b. What was the sample? c. Why did the sample results differ from the population? d. What are two constants that might have limited the generalizability of the polling results?

3. The director of library services at Fairmont College did a survey of types of books (by subject) in the circulation library. Then she used library records to take a random sample of 4217 books checked out last term and classified the books in the sample by subject. The results are shown below. Subject Area % Books in Circ Library on this Subject No. of Books in the Sample on this Subject Business 32% 1210 Humanities 25% 956 Natural Science 20% 940 Social Science 15% 814 Other Subject 8% 297 Using a 5% level of significance, test the claim that the subject distribution of books in the library fits the distribution of books checked out by students.

A survey of 200 randomly selected college students was conducted to determine if the campus library should extend its hours of operation. The results of the survey are in the table. Closing Time Preference Close at 8 p.m. Close at 10 p.m. Close at midnight Year in College Freshmen Sophomores 25 15 20 15 5 25 Juniors 10 25 15 Seniors 25 15 5 If there are 4,000 students at the college, what is the best estimate for the number of students who prefer the library to close at 10 p.m.? O 1,000 students 1 200 students Next ▸ US 9:48 < Previous % A O DELL & ★ ME

Human blood is classified by the presence or absence of three main antigens (A, B, and Rh). When a blood specimen is typed, the presence of the A and/or B antigen is indicated by listing the letter A and/or the letter B. If neither the A nor the B antigen is present, the letter O is used. The following table gives the percent of a country's population having each of the eight possible blood types in the sample space. Note that the presence or absence of the Rh antigen is indicated by the symbols + or -, respectively. 0 Blood Types Percent A+ A 6.3 35.7 B+ B 8.5 1.5 AB+ AB 3.4 0.8 0+ 37.2 (a) What is the probability that a person selected at random from the population has a blood type that is type A given that the person is Rh? (Round your answer to two decimal places.) 6.6 (b) What is the probability that a person selected at random from the population has a blood type that is Rh* given that the person is type B? (Round your answer to two decimal places.)

The management of Discount Furniture, a chain of discount furniture stores in the Northeast, designed an incentive plan for salespeople. To evaluate this innovative plan, 12 salespeople were selected at random, and their weekly incomes before and after the plan were recorded.      Salesperson Before After Sid Mahone   $ 320       $ 340     Carol Quick     290         285     Tom Jackson     421         475     Andy Jones     510         510     Jean Sloan     210         210     Jack Walker     402         500     Peg Mancuso     625         631     Anita Loma     560         560     John Cuso     360         365     Carl Utz     431         431     A. S. Kushner     506         525     Fern Lawton     505         619           Hint: For the calculations, assume the "Before" data as the first sample.        Click here for the Excel Data File     State the decision rule for 0.05 significance level: H0: μd ≥ 0 and H1: μd < 0. (Negative values should…

Human blood is classified by the presence or absence of three main antigens (A, B, and Rh). When a blood specimen is typed, the presence of the A and/or B antigen is indicated by listing the letter A and/or the letter B. If neither the A nor the B antigen is present, the letter O is used.The following table gives the percent of a country's population having each of the eight possible blood types in the sample space. Note that the presence or absence of the Rh antigen is indicated by the symbols + or −, respectively. Blood Types A+ A− B+ B− AB+ AB− O+ O− Percent 35.7 6.1 9.5 1.5 3.4 0.8 37.4 5.6 (a) What is the probability that a person selected at random from the population has a blood type that is type A given that the person is Rh−? (Round your answer to two decimal places.)(b) What is the probability that a person selected at random from the population has a blood type that is Rh+ given that the person is type B? (Round your answer to two decimal places.)