Day 8.5 HW Sampling Distributions Practice 1. The Wechsler Adult Intelligence Scale (WAIS) is a common "IQ test" for adults. The distribution of WAIS scores for persons over 16 years of age is approximately normal with mean 100 and standard deviation 15. a. What is the probability that a randomly chosen individual has a WAIS score of 105 or higher? Show your work. P ( * > 105 ) = 1 DD b. What are the mean and standard deviation of the sampling distribution of the average WAIS score x for a SRS of 60 people? A = 60 Mxam = 100 15 = 1.93 VGo What is the probability that the average WAIS score of an SRS of 60 people is 105 or higher? Show your work. P(x 7 105 ) =,0049 2. Suppose that 47% of all adult women think they do not get enough time for themselves. An opinion poll interviews 1025 randomly chosen women and records the sample proportion who feel they don't get enough time for themselves. a. The truth about the population is p = 0.47. In what range will the middle 95% of the sample results fall? P=: 47 0= 1025 92,53 61438, 1502 Op = 1 471.53 = 0.016 . 47 + 26.010 ) b. What is the probability that the poll gets a sample in which fewer than 45% say they do not get enough time for themselves? P ( p