Assume that the amount of time that it takes an employee to service a car at an oil change facility follows the uniform probability distribution between 21 and 38 minutes.

What is the standard deviation of this distribution

a.4.91

b.6.62

c.9.75

d.11.8

Option A - 4.91

Step-by-step explanation:

The formula for theoretical standard deviation of uniform distribution is;

σ = √{(b-a)^2}/12

Now from the question, b = 38 minutes and a= 21 minutes

Therefore, σ = √{(38-21)^2}/12

= √{17^2}/12 = √289/12 = 4.907 which is approximately 4.91