(58 / 50) - 1 = 16%. Fill in the chart (Just column a) through December. Then find Standard deviation and expected return

Enter all 12 returns with your HP 10BII+ calculator. Push Sigma+ after each return. When done, push [shift] 7 to get the expected return, and push [shift] 8 to get the standard deviation.

4.9 is the expected return and 7.81% is the standard deviation........ i just dont see how they got that answer i put all the numbers into the calculator and couldnt get it

(a) monthly return (b expected month price return $50,00 $58.000.160 Jan Feb Mar Apr May 63.80 $59.00 $62.00 64.50 69.00 Aug Sep 75.00 $82.50 9 Nov Dec 80.00 $86.00 (a) monthly return (b expected month price return $50,00 $58.000.160 Jan Feb Mar Apr May 63.80 $59.00 $62.00 64.50 69.00 Aug Sep 75.00 $82.50 9 Nov Dec 80.00 $86.00