In: Statistics and Probability
29; 37; 38; 40; 58; 67; 68; 69; 76; 86; 87; 95; 96; 96; 99; 106; 112; 127; 145; 150
What is the Standard deviation (please round to two decimal places)?
Solution:
Given that,
29; 37; 38; 40; 58; 67; 68; 69; 76; 86; 87; 95; 96; 96; 99; 106; 112; 127; 145; 150
The mean of sample is
x/n = (29+37+38+ 40+5+67+68+69+ 76+86+ 87+95+96+ 96+ 99+106+ 112+ 127+ 145+150) / 20
= 81.4
The sample mean is 81.4
Sample standard deviation is s
s = 1/(n-1)(x - )2
= 1/4 (29 - 81.4 )2+ (37-81.4)2+ (38 - 81.4)2+ (40- 81.4 )2 +( 58- 81.4)2+ (67 -81.4)2+ (68 - 81.4 )2+ (69- 81.4)2 +( 76 - 81.4 )2+ (86 - 81.4 )2+ (87 - 81.4 )2+ (95- 81.4 )2 +( 96 - 81.4)2+ (96 -81.4 )2+ (99 - 81.4 )2+ (106- 81.4 )2 +( 112 - 81.4 )2+ (127 - 81.4)2+ (145 -81.4)2+ (150- 81.4 )2
= 1477.2
= 38.434359627812
The sample standard deviation is =38.43