Question 3 (7 points)

3. Let Y = the number of siblings for a student at a local high school. Suppose we choose someone from the school at random. The probability

distribution of Y is as follows.

Y

1

2

3

4

5+

0

0. 02

Probability

0. 25

0. 35

0. 20

0. 10

0. 08

(a) Is Y a discrete or continuous? Explain.

(b) Is this a valid probability distribution? Explain.

(c) Create a histogram for the probability distribution and describe its shape.

(d) Find the probability that the randomly selected student has at least one sibling.

(e) Describe in words what P[Y>2) means and find the probability.

(1) Calculate the mean of Y. Interpret this in context

(g) The standard deviation is 1. 236. Interpret this in context.

BI U EES s T