A typical adult has an average IQ score of 105 with a standard deviation of 20. If 20 randomly selected adults are given an IQ test, what is the probability that the sample mean scores will be between 85 and 125 points? Assume IQ scores are normally distributed. The average length of a maternity stay in a U.S. hospital is said to be 2.4 days with a standard deviation of 0.9 days. We randomly survey 80 women who recently bore children in a U.S. hospital. 7.3 # 90 a. Would it be unusual for an individual to stay more than three days in the hospital? Why or why not? b. Would it be unusual for the average stay for the 80 women to be more than three days? Why or why not?