## Introductory Statistics 9th Edition

a. Range = Highest value- Lowest value = 53-10=43 $Variance = σ^2=(∑〖(x-μ)〗^2 )/N$ $=[∑(x^2) -∑(x)^2]/N$ $=[12649-10620.75]/12$ =129.0208 Standard Deviation = $\sqrt 129.0208= 13.0008$ b. Coefficient of Variation = $13.0008\div29.75 \times100% = 43.70%$