Question

According to insurance records, a car with a certain protection system will be recovered 85% of the time. If 100 stolen cars are randomly selected, what is the mean and standard deviation of the number of cars recovered after being stolen?

Answer 1

Write 85% as a decimal: 0.85

To find the mean, multiply the sample by the percentage:

Mean = 100 x 0.85 = 85

The standard deviation formula: √n*p*(1-p)

n = sample

p = percentage

Standard deviation = √(100 * 0.85 * (1-0.85)

Standard deviation = 3.57