Answer
a. Range = 23, Variance = 45.6079, Standard Deviation = 6.7534
b. Coefficient of Variation = 22.62%
Work Step by Step
a. Range = Highest Value - Lowest Value = 42-19=23
Variance = $σ^2=(∑〖(x-μ)〗^2 )/n-1 $
$=[∑(x^2) -∑(x)^2]/N/n-1$
$=[18687-(597^{2}/20)/19]$
$=(18687-17820.45)/19$
$=45.6079$
Standard Deviation = $\sqrt45.6079 = 6.7534$
b. Coefficient of Variation=$6.7534\div29.85\times100% =22.62%$
