Question
please help
The National Association of Colleges and Employers recently published that 2013 graduates with a business degree had an average starting salary of $54,000 per year. Suppose starting salaries are normally distributed and the standard deviation is $7500. If your salary is in the upper 10% of all starting salaries, at the minimum, how much do you earn? a. $63, 600 b. $58, 048.50 c. $65, 250 d. $44, 400 e. $60, 750 f. $54, 750 Data accumulated by NOAA shows that the average annual precipitation for St. Louis, MO is 34 inches. If 22.21% of the time, the annual precipitation is more than 40 inches, what is the standard deviation for annual precipitation in St. Louis? a. 3.702 b. 7.713 c. 27.015 d. 7.843 d. 7.843 e. 765 f. 7.551
Explanation / Answer
4) for top 10% ; z=1.28
therefore corresponding salary =sample mean +z*std deviation=54000+1.28*7500=63600
option A is correct
5)
for highest 22.21% ; z=0.7651
therefore std deviation =(40-34)/0.7651=7.843
option d