Question

Which of the choices is the standard deviation of the sample shown here?

19, 20, 21, 22, 23

A.2.5
B.21
C.square root of 2.5
D.2
E.square root of 2

Answer 1

C for apex

Explanation:

Answer 2

Mean = (19 + 20 + 21 + 22 + 23)/5 = 105/5 = 21
x x - mean (x - mean)^2
19 -2 4
20 -1 1
21 0 0
22 1 1
23 2 4
Sum = 10

Standard deviation = sqrt(sum(x - mean)^2 /n) = sqrt(10/5) = sqrt(2)