Question

HELP PLEASE!!

Answer 1

Add them all up the divide by the number of numbers there are ok.You will need to add them all up divide by 12.

Answer 2

1.52  
First, let's calculate the standard deviation. So first, let's calculate the mean:
 M = (135+71+69+80+158+152+161+96+122+118+87+85)/12
 M = 1334/12 = 111.1666667 
 Now the mean of the squares from the mean. So:
 (135-111.1666667)^2 = 23.83333333^2 = 568.0277778
 (71-111.1666667)^2 = -40.16666667^2 = 1613.361111
 (69-111.1666667)^2 = -42.16666667^2 = 1778.027778
 (80-111.1666667)^2 = -31.16666667^2 = 971.3611111
 (158-111.1666667)^2 = 46.83333333^2 = 2193.361111
 (152-111.1666667)^2 = 40.83333333^2 = 1667.361111
 (161-111.1666667)^2 = 49.83333333^2 = 2483.361111
 (96-111.1666667)^2 = -15.16666667^2 = 230.0277778
 (122-111.1666667)^2 = 10.83333333^2 = 117.3611111
 (118-111.1666667)^2 = 6.833333333^2 = 46.69444444
 (87-111.1666667)^2 = -24.16666667^2 = 584.0277778
 (85-111.1666667)^2 = -26.16666667^2 = 684.6944444 
 And their mean:
 (568.0277778+1613.361111+1778.027778+971.3611111+2193.361111+1667
.361111+2483.361111+230.0277778+117.3611111+46.69444444+584.027777
8+684.6944444)/12
 = 12937.66667/12 = 1078.138889 
 And finally, the square root:
 SDEV = sqrt(1078.138889)
 SDEV = 32.83502534 
 So the mean is 111.1666667 and the standard deviation is 32.83502534. 
 Let's determine how far from the mean the lowest and highest values are:
 Low 69 = 69 - 111.1666667 = -42.16666667
 High 161 = 161 - 111.1666667 = 49.83333333 
 The high value is further away from the mean than the low value. The
number of standard deviations from the mean si:
 49.83333333 / 32.83502534 = 1.517688286 
 Rounding to 3 figures gives an answer of 1.52