Question

There are two toy shops in Chicago, in East Street and West Street. The mean monthly sales at East and West are equal, however the manager at the East Street believes his sales are more consistent. With the 0.01 significance level, can we conclude that his statement is true?

Below is the number of toys sold at East Street in the last seven months and for the last eight months at West Street :

East Street

98

78

54

57

68

64

70

West Street

75

81

81

30

82

46

58

101

Answer 1

	East Street (x)	x2
	98	9604
	78	6084
	54	2916
	57	3249
	68	4624
	64	4096
	70	4900
Total	489	35473

Here

n = 7

	West Street(y)	y2
	75	5625
	81	6561
	81	6561
	30	900
	82	6724
	46	2116
	58	3364
	101	10201
Total	554	42052

Here

n = 8

The coefficient of variation (CV) is a measure of relative variability. It is the ratio of the standard deviation to the mean (average).

The data having lower coefficient of variation is more consistent and vice - versa.

The coefficient of variation for East Street (x) has lower than the coefficient of variation for west street (y).

So, it is conclude that  his sales at the East Street are more consistent.