Question

Find the standard deviation of the words per page. 10 15 8 16 14 12 9 12 14 10

Answer 1

standard deviation = 2.56 .

Explanation:

We have to find the standard deviation of :

10, 15, 8 ,16, 14, 12, 9,12, 14, 10

The formula to find standard deviation is:

S.D = ∑(x-mean)² / n where n is total number of values.

The mean is the sum of total values divided by the number of values.

The mean=( 10+ 15+8 +16+14+ 12+ 9+12+ 14+ 10) / 10 = 12

(x- mean) = -2 , 3 ,-4 , 4 , 2 , 0 , -3 , 0 , 2 , -2 .

(x- mean)² = 4, 9,16, 16, 4, 0, 9, 0, 4, 4.

∑(x- mean)² = 4+9+16+ 16+4+ 0+ 9+0+ 4+ 4= 6

n = 10

Putting values in formula, we have

standard deviation =√66/10

S.D= 2.56 which is the answer.

Answer 2

Standard deviation = 2.569

Explanation:

The mean = (10 + 15 + 8 + 16 + 14 + 12 + 9 + 12 + 14 + 10) ÷ 10 = 12

x - mean = -2 , 3 , -4 , 4 , 2 , 0 , -3 , 0 , 2 , -2

(x - mean)² = 4 , 9 , 16 , 16 , 4 , 0 , 9 , 0 , 4 , 4

Σ(x - mean)² = 4 + 9 + 16 + 16 + 4 + 0 + 9 + 0 + 4 + 4 = 66

Standard deviation = √(66/10) = 2.569