22) Construct a 90% confidence interval for the population mean, u. Assume the population has a 22) normal distribution. A sample of 15 randomly selected math majors has a grade point average of 2.86 with a standard deviation of 0.78. Round to the nearest hundredth. A) (2.28, 3.66) B) (2.41, 3.42) C) (2.37, 3.56) D) (2.51, 3.21) 23) Find the standardized test statistic t for a sample with n = 25, x = 12, s =3, and a = 0.005 if 23) H1: p > 11. Round your answer to three decimal places. A) 1.452 B) 1.239 C) 1.667 D) 1.997 24) The National Association of Realtors estimates that 23% of all homes purchased in 2004 were 24) considered investment properties. If a sample of 800 homes sold in 2004 is obtained what is the probability that at most 200 homes are going to be used as investment property? A) 0.5935 B) 0.4066 C) 0.9099 D) 0.0934 25) A physical fitness association is including the mile run in its secondary-school fitness test. The time 25) for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 40 seconds. Between what times do we expect most (approximately 95%) of the boys to run the mile? A) between 371.6 and 528.4 sec B) between 384.2 and 515.824 sec C) between 355 and 545 sec D) between 0 and 515.824 sec 26) A researcher at a major clinic wishes to estimate the proportion of the adult population of the 26) United States that has sleep deprivation. How large a sample is needed in order to be 90% confident that the sample proportion will not differ from the true proportion by more than 4%? A) 423 B) 846 C) 256 D) 11 27) A doctor at a local hospital is interested in estimating the birth weight of infants. How large a 27) sample must she select if she desires to be 99% confident that her estimate is within 2 ounces of the true mean? Assume that s = 7 ounces based on earlier studies. A) 10 B) 9 C) 81 D) 82 28) Assuming that all conditions are met to approximate a binomial probability distribution with the 28 ) standard normal distribution, then to compute P(12 s x s 15) from the binomial distribution we must compute as the normal approximation. A) P(11.5 12.5) and P(x 15.5) and P(x