Question

QUESTION 9 Solve the problem. The coefficient of variation, expressed as a percent, is used to describe the standard deviation relative to the mean. It allows us to compare variability of data sets with different measurement units and is calculated as follows: coefficient of variation- 100 (s/x Find the coefficient of variation for the following sample of weights (in pounds): 152 120 186 105 197 128 172 160 116 125 23.9% 19.1% 21.8% o 26.8%

Answer 1

QUESTION 9:

Sample mean = = 1461/10 = 146.1

x	x -	(x - )2
152	5.9	34.81
120	- 26.1	681.21
186	39.9	1592.01
105	- 41.1	1689.21
197	50.9	2590.81
128	- 18.1	327.61
172	25.9	670.81
160	13.9	193.21
116	- 30.1	906.01
125	- 21.1	445.21
Total =		9130.9

Sample standard deviation (s) is given by:

Coefficient of Variation is given by:

%

So,

Correct option:

21.8 %

QUESTION 10:

Class mid point for class 235.0 - 265.9 is given by:

So,

Correct option:

250.45