156 CHAPTER 4 Probability xY or Yx pair of chromosomes will have the disease and a child with XX or XY or YX or xX or Xx will not have the disease. Each parent contributes one of the chromosomes to the child. a. If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a son will inherit the disease? b. If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a daughter will inherit the disease? c. If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a son will inherit the disease? d. If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a daughter will inherit the disease? Probability from a Sample Space. In Exercises 29–32, use the given sample space or construct the required sample space to find the indicated probability. 29. Three Children Use this sample space listing the eight simple events that are possible when a couple has three children (as in Example 2 on page 146): {bbb, bbg, bgb, bgg, gbb, gbg, ggb, ggg}. Assume that boys and girls are equally likely, so that the eight simple events are equally likely. Find the probability that when a couple has three children, there is exactly one girl. 30. Three Children Using the same sample space and assumption from Exercise 29, find the probability that when a couple has three children, there are exactly two girls. 31. Four Children Exercise 29 lists the sample space for a couple having three children. After identifying the sample space for a couple having four children, find the probability of getting three girls and one boy (in any order). 32. Four Children Using the same sample space and assumption from Exercise 31, find the probability that when a couple has four children, all four are of the same gender. Using Probability for Signifiance. In Exercises 33–40, use the given probability value to determine whether the sample results are significant. 33. Voting The County Clerk in Essex, New Jersey, was supposed to use randomness to assign the order in which candidates’ names appeared on voting ballots. Among 41 different ballots, Democratic candidate names were placed on the first line 40 times. The probability of a result that high is 0.0000000000191. Assuming randomness was used, is the result of 40 Democratic candidate names being placed on the first line significantly low, significantly high, or neither? 34. Voting Repeat the preceding Exercise 33 after replacing 40 Democrats being placed on the first line of voting ballots with 26 Democrats being placed on the first line. The probability of getting a result as high as 26 is 0.058638. 35. Voting Repeat Exercise 33 after replacing 40 Democrats being placed on the first line of voting ballots with 14 Democrats being placed on the first line. The probability of getting a result as low as 14 is 0.029792. 36. Voting Repeat Exercise 33 after replacing 40 Democrats being placed on the first line of voting ballots with 27 Democrats being placed on the first line. The probability of getting a result as high as 27 is 0.029792. 37. Predicting Gender A study addressed the issue of whether pregnant women can correctly predict the gender of their baby. Among 104 pregnant women, 57 correctly predicted the gender of their baby (based on data from “Are Women Carrying ‘Basketballs’ . . . ,” by Perry, DiPietro, Constigan, Birth, Vol. 26, No. 3). If pregnant women have no such ability, there is a 0.189 probability of getting 57 or more correct predictions in 104 births. Is 57 correct predictions significantly low, significantly high, or neither? What do you conclude about the ability of pregnant women to correctly predict the gender of their baby? 38. Getting a Job In an SHRM survey of 410 human resource workers, it was found that 148 of these workers have turned down job applicants because of information they found on social media.
RkJQdWJsaXNoZXIy NjM5ODQ=