Factory A and Factory B employ 476 and 524 employees. respectively. The average weekly salary of an employee in Factory A is $34.5 whereas for an employee in Factory B it is $28.5, The standard deviation in paying the individual salary has been recorded as $5 and $4.5 for Factory A and Factory B, respectively. Which factory has greater variability in paying individual salary?
Factory A and Factory B employ 476 and 524 employees. respectively. The average weekly salary of an employee in Factory A is $34.5 whereas for an employee in Factory B it is $28.5, The standard deviation in paying the individual salary has been recorded as $5 and $4.5 for Factory A and Factory B, respectively. Which factory has greater variability in paying individual salary? Correct Answer B
Given
Average weekly wages of factory A = 34.5
Average weekly wages of factory B = 28.5
Number of employees engaged in factory A = 476
Standard deviation (σ)A = $5
Standard deviation (σ)B = $4.5
Formula
For answering the question we have to find out the coefficient of variation
Coefficient of variation =( S.D. x 100 )/average wages
Calculation
coefficient of variation for factory A
⇒ ( 5.0 x 100 ) /34.5
⇒ 14.49
Coefficient of variation for factory B
⇒ ( 4.5 x 100 ) / 28.5
⇒ 15.78
Higher the coefficient of variation, the higher the variability of individual wages.
∴ Factory B is having higher variability in individual wages.
If we square the standard devation we will get variance, therefore
Variance = σ2 =
For example
The standard deviation of 5, 10, 20 and 25 is
Mean = (5 + 10 + 20 + 25)/4 = 15
SD = σ = √
σ = √
σ = √[(1/4)(250
σ = √125/2
Variance = σ2 = 125/2
Coefficient of variation = (Standard deviation/mean) × 100
(σ/x̅)× 100