Have to come to work on time for atleast 80% of the shifts. Noticed 23 out of 35 workers on time. What is the probability that 23 of 35 will come on time if underlying rate is 80%

Question

The captain has set goal for everyone to be on time for atleast 80% of the shifts. In one day there are 35 people working shifts. You noticed 23 of them on time. What is the probability of having 23 of 35 people on time if underlying rate is 80%.

A. 2.02%

B. 2.43%

C. 3.44%

D. 4.79%

Answer 1

Here we can use the binomial distribution where n=35, x=23 and p=0.8

23 12

C (0.8) (0.2) = 0.0202 = 2.02% (A).

35 23