Solar energy cells. According to the Earth Policy Institute

(July 2013), 60% of the world’s solar energy cells are manufactured in China. Consider a random sample of 5 solar energy cells, and let x represent the number in the sample that are manufactured in China. In Section 4.4, we show that the probability distribution for x is given by the formula p1x2 =

15!21.62x1.425-x 1x!215-x2!

, where n! = 1n21n-121n-22c122112

a. Explain why x is a discrete random variable.

b. Find p(x) for x = 0, 1, 2, 3, 4, and 5.

c. Show that the properties for a discrete probability distribution are satisfied.

d. Find the probability that at least 4 of the 5 solar energy cells in the sample are manufactured in China.