Question

(i) Calculate the mean and standard deviation for these weekly incomes.

Answer 1

Answer:

Mean = 272.3

sd = 37.7

Step-by-step explanation:

Mean = sum/n

(221+248+251+255+259+263+264+272+291+297+374) ÷ 11

= 2995/11

= 272.2727273

Variance = (sum of x²)/n - mean²

[(221²+248²+251²+255²+259²+263²+264²+272²+291²+297²+374²)/11] - (2740/11)²

= (831067/11) - (2995/11)²

= 1419.107438

sd² = variance

sd = sqrt(1419.107438)

sd = 37.67104243