Dee's store monthly sales for April, May, June are three independent random variables with means and variances as follow:
April:
Mean: $9500
Variance: $1250
May:
Mean: $7400
Variance: $1425
June:
Mean: $8600
Variance: $1610
a) find the mean and standard deviation of the total sales for the 2nd quarter (3 month period).
-for mean, do you just add the means together and for stdev, do you just add the variance together and square root it?
b) If the store manager is paid by a base monthly salary of $2000 plus 10% of the monthly sales as commission, what is the mean and standard deviation of his monthly salary for May?
-how do you do this part?