Andrew plans to retire in40 years.He plans to invest part of his retirement funds in stocks, so he seeks out information on past returns. He learns that from 1969 to 2018, the annual returns on S&P500had a meanof 9.8%and a standard deviationof 16.8%.The mean return over even a moderate number of years is close to Normal.

What is the probability,1,(assuming that the past pattern of variation continues) that the mean annual return on common stocks over the next40 yearswill exceed10%?Give your answer to two decimal places.

1=

What is the probability,2,that the mean return will be less than5%?Give your answer to two decimal places.

2=

To estimate the mean scoreof those who took the Medical College Admission Test on your campus, you will obtain the scores of an SRS of students. From published information you know that the scores are approximately Normal with a standard deviation of about6.3.You want your sample meanto estimatewith an error of no more than1.3 pointsin either direction.

What standard deviation musthave so that99.7%of all samples give anwithin1.3 points of? Use the68-95-99.7rule. Give your answer to four decimal places.

the standard deviationof =

How large an SRS do you need in order to reduce the standard deviation ofto the value you found? Give your answer rounded up to the nearest whole number.

SRS size: