P100 ⬍ y ⬍ 108 Lyman Ott Michael Longnecker

4.68 Find the probability of observing a value of z greater than these values. a. 1.96

b. 2.21 c. ⫺2.86

d. ⫺0.73

Gov. 4.69 Records maintained by the office of budget in a particular state indicate that the amount of time elapsed between the submission of travel vouchers and the final reimbursement of funds has approximately a normal distribution with a mean of 39 days and a standard deviation of 6 days.

a. What is the probability that the elapsed time between submission and reimbursement

will exceed 50 days?

b. If you had a travel voucher submitted more than 55 days ago, what might you

conclude? Edu. 4.70 The College Boards, which are administered each year to many thousands of high school students, are scored so as to yield a mean of 500 and a standard deviation of 100. These scores are close to being normally distributed. What percentage of the scores can be expected to satisfy each condition?

a. Greater than 600 b. Greater than 700

c. Less than 450 d. Between 450 and 600

Bus. 4.71 Monthly sales figures for a particular food industry tend to be normally distributed with mean of 150 thousand dollars and a standard deviation of 35 thousand dollars. Compute the following probabilities:

a. Py ⬍ 200 b. Py ⬎ 100

c. P100 ⬍ y ⬍ 200 4.72 Refer to Exercise 4.70. An exclusive club wishes to invite those scoring in the top 10 on the College Boards to join. a. What score is required to be invited to join the club? b. What score separates the top 60 of the population from the bottom 40? What do we call this value? 4.11 Random Sampling Soc. 4.73 City officials want to sample the opinions of the homeowners in a community regarding the desirability of increasing local taxes to improve the quality of the public schools. If a random number table is used to identify the homes to be sampled and a home is discarded if the home- owner is not home when visited by the interviewer, is it likely this process will approximate random sampling? Explain. Pol. 4.74 A local TV network wants to run an informal survey of individuals who exit from a local vot- ing station to ascertain early results on a proposal to raise funds to move the city-owned historical museum to a new location. How might the network sample voters to approximate random sampling? Psy. 4.75 A psychologist is interested in studying women who are in the process of obtaining a divorce to determine whether the women experienced significant attitudinal changes after the divorce has been finalized. Existing records from the geographic area in question show that 798 couples have recently filed for divorce. Assume that a sample of 25 women is needed for the study, and use Table 13 in the Appendix to determine which women should be asked to participate in the study. Hint: Begin in column 2, row 1, and proceed down. Pol. 4.76 Suppose you have been asked to run a public opinion poll related to an upcoming election. There are 230 precincts in the city, and you need to randomly select 50 registered voters from each precinct. Suppose that each precinct has 1,000 registered voters and it is possible to obtain a list of these persons. You assign the numbers 1 to 1,000 to the 1,000 people on each list, with 1 to the