Answer:
81.25 ; 3091.48 ; 55.60
Step-by-step explanation:
Given the data :
45, 60, 25, 55, 75, 90, 100, 120, 105, 80, 0, 220
The mean :
ΣX/n ; n = sample size
ΣX = 45+60+25+55+75+90+100+120+105+80+0+220 = 975
n = 12
Mean = 975 / 12 = 81.25
The variance :
Σ(X - m)^2 / n - 1
Using calculator to save computation time :
The variance : (34006.24997 / 11)
Variance = 3091.48
The standard deviation :
Sqrt(Variance) = sqrt(3091.48) = 55.60
