In order to study the return on assets in the bio-techinlohy industry, a sample of cmpanies was selected randomly. Their rate of returns (X in percent) are shown in the attached document.
A) Prepare stem and leaf display
B) Calculate the mean rate of return and standard deviation of the rates of return
C) If the reat of return for a new company is 30.5 oercent, would this be considered unusual? Jusify your answer
D) Assume the distribution of rates of return is mound-chapes, estimate the percentage of all bio-tech companies for which the reate of return is 15.99% or more