Question

Janelle runs a janitorial service that cleans doctor's offices. Janelle tracks the hours

Answer 1

Answer:

The percentage  of nights does it take employees less than 3 hours to clean the largest  building  

 P( x < 3) = 2.28 hours

Step-by-step explanation:

Step(i):-

Given mean of the Population = 3.8 hours

Given Standard deviation of the Population = 0.4 hours

Let 'X' be the random variable in Normal distribution

Let 'X' = 3 hours

$Z = \frac{x-mean}{S.D}$

$Z = \frac{3-3.8}{0.4} = - 2$

Step(ii):-

The probability that  nights does it take employees less than 3 hours to clean the largest  building

P( x < 3) = P(Z < -2)

            = 0.5 -A(-2)

           = 0.5 - A(2)

          =  0.5 - 0.4772

          = 0.0228

The probability that  nights does it take employees less than 3 hours to clean the largest  building

P( x < 3) = 0.0228

Conclusion:-

The percentage  of nights does it take employees less than 3 hours to clean the largest  building  

 P( x < 3) = 2.28   hours