Question

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

18, 19, 20, 21, 22

A) 2.5
B) 20
C) /2.5
D) /2
E) 2

Answer 1

Answer: It’s C

Explanation:

Answer 2

(D)

Explanation:

The given data set is:

18, 19, 20, 21, 22

Mean of the given data set is given as:

`Mean=(18+19+20+21+22)/(5)`

`Mean=(100)/(5)`

`Mean=20`

Now,

Data values
`(x-{\overline{x})^2`

18 4

19 1

20 0

21 1

22 4

Now, variance is given as:

`V=(4+1+0+1+4)/(5)`

`V=2`

The standard deviation is the square root of the variance, thus

`SD=√(V)`

`SD=√(2)`

Thus, option (D) is correct.