Question:**Could you double check my calculation for standard deviation. Thank you.**

A. Calculate the mean and standard deviation of the following securities' returns:

Year Computroids Inc. Blazers Inc.

1 10% 5%

2 5% 6%

3 -3% 7%

4 12% 8%

5 10% 9%

Computroids Inc.

mean/E(r) = (10%+5% - 3% + 12% + 10%) /5 =6.8

standard deviation = sqrt{[(.1-068)²+(.05-068)²+(-.03 - 068)²+(.12-068)²+(.1-.068)²] / 5-1} = 5.418

= sqrt{[0.001 + 0.0003 + 0.0096 + 0.0027 + 0.001] / 4} =

= sqrt{0.0147/4}

= sqrt{0.0037}

= 0.0606