1. Suppose 30% of the Audi sold inAmerica were made in Germany. A sample of 20 BMWs were taken. What is the probability that 10 or fewer the selectedAudi were made outside Germany?

2. If X is a normal random variable with a standard deviation of 10, then 5X has a standard deviation equal to

3. The number of customers shopping at a websitefollows a Poisson distribution with a mean of 10 people per hour. The probability that over the next hour 6 people will shop at thewebsite is

4. Assume that the lifetime of a bulb is normally distributed, with a mean of 2,500 hours and a standard deviation of 100 hours. If the city council wants no more than 4% of the bulbs to burn out before they are replaced, after how many hours should all of the bulbs be replaced?

5.A nurse has to call each patient a week before their bill is due. As a result of time constraints, however, only 60% of patients receive such a call from his nurse. Of the patients called, 90% pay on time, while only 30% of those not called pay on time. Dr. Ho has just received a payment on time from a patient.

What is the probability that the nurse did not call this patient?

6. What proportion of the data from a normal distribution is within 1.4 standard deviations of the mean?

7. Four people are applying for a job. Employing the subjective approach,the employerhas assigned the following probabilities that these applicants will be hired:

P(A) = 0.41

P(B) = 0.10

P(C) = 0.27

P(D) = 0.22

The probability that either B or C are hired is ?

8.The number of customers paying with PayPal is Poisson distributed. The mean number of such users per 5-minute interval is 1.5. The probability that no such users in the next 10 minutes is ?

9. The following shows the probability distribution of the number ofclothes a customer buys at a store per day (X).

x 1 2 3 4 5 6 7

P(x) 0.05 0.15 0.15 0.25 0.20 0.10 0.10

The probability that more than fiveclothes are bought is ?

10. The result of a quiz follows a normal distribution with a mean of 75 marks and a standard deviation of 2.5 marks. The probability of randomly selecting a student whose mark is lower than 80 is ?