Question

A person is interested in studying the amount of time (in minutes) people spend on social media in day. The following data is collected from a sample of 12 people: 45, 60, 25, 55, 75, 90, 100, 120, 105, 80, 0, and 220. (a) Calculate the mean, variance and standard deviation and 5

Answer 1

81.25 ; 3091.48 ; 55.60

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