Suppose that the sick leave taken by the typical worker per year has

= 10,

= 2, measured in days. A firm has n = 30 employees. Assuming independence, how many sick days should the firm budget if the financial officer wants the probability of exceeding the number of days budgeted to be less than 20%.

## EXPERT ANSWER

Solution,

Given that,

mean = = 10

standard deviation =

n = 30

Using standard normal table,

P(Z > z) = 20%

=1 – P(Z < z ) = 0.20

= P(Z < z ) = 1 – 0.20

= P(Z < 0.84 ) = 0.80

z = 0.84

Using z-score formula