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The ages, in years, of 5 boys are 5, 6, 6, 8 and 10. Calc...

The ages, in years, of 5 boys are 5, 6, 6, 8 and 10. Calculate, correct to one decimal place, the standard deviation of their ages.

A.

3.2 years

B.

2.6 years

C.

1.9 years

D.

1.8 years

Correct answer is D

x 5 6 6 8 10 Total
xˉx -2 -1 -1 1 3  
(xˉx)2 4 1 1 1 9 16

Mean (ˉx) = 5+6+6+8+105

= 355=7

SD=(xˉx)2n

= 165

= 3.2