King Fahd University of Petroleum & Minerals
Department of Mathematical Sciences
Stat. 319, Quiz 3 (semester 043)
SECTION: 2
INSTRUCTOR: MUSAWAR MALIK
NAME:
ID #:
1. Suppose that milk is shipped to retail outlets in boxes that hold 20 milk containers,
one particular box, which happens to contain 5 underweight containers, is opened for
inspection, and 4 containers are chosen at random.
a. What is the distribution of the number of underweight milk containers in the
sample chosen by the inspector?
b. Find the probability that the inspector chooses exactly two underweight containers
2. For a certain manufacturing industry the average number of industrial accidents per
week is 4. Find the probability that
a. At most 3 accidents in 2 weeks.
b. At least 2 accidents in 3 weeks.
3. The experience of a house agent indicates that he can provide suitable
accommodation for 75 percent of the clients who come to him. If on a particular
occasion, 6 clients approach him independently, calculate the probability that at least
five clients will get satisfactory accommodation.
4.
Pale magnetic studies of Canadian volcanic rock known as the Carmacks Group
have recently been completed. The studies revealed that the northward displacement
of the rock units has an approximately normal distribution with standard deviation of
500 kilometers (Canadian Journal of Earth Sciences, Vol. 27, 1990). One group of
researchers estimated the mean displacement at 1,500 km, whereas a second group
estimated the mean at 1,200 km.
(a). Assuming the mean is 1,500 km, what is the probability of a northward
displacement of less than 500 km?
(b). Assuming the mean is 1,200 km, what is the probability of a northward
displacement of less than 500 km?