Question

1. Every two seconds someone in America needs blood. It is important that hospitals have the right types of quality
blood to meet the patient needs. Blood donation centers help hospitals meet this demand. There are four main
blood groups: A, B, AB, and O, of which O is the most common. One of the less common blood types is B+. In
the United States, only 9% of the population has B+ blood type.
Assume that 5 donors arrive to a blood donation center and you are interested in the number of these donors that
have B+ blood type. Therefore, let X be the random variable that represents the number of donors with B+ blood

a) What type of distribution is the random variable X?
b) CENTRAL TENDENCY: Calculate the mean of X
c) DISPERSION OR SPREAD: Calcuate the variance and standard deviation of X
d) SHAPE: Create the probability mass function of X in graphical format
e) SHAPE: Create the cumulative distribution function of X in graphical format.
type among the 5 donors that came to the center.

2.

Inhabitants	1	2	3	4	5	6	7
Probability	0.25	0.32	0.17	0.15	0.05	0.03	0.03

a.) What type of distribution is the random variable X?
b) CENTRAL TENDENCY: Calculate the mean of X.
c) DISPERSION OR SPREAD: Calcuate the variance and standard deviation of X.
d) SHAPE: Create the probability mass function of X in graphical format
e) SHAPE: Create the cumulative distribution function of X in graphical format.
f) POSITION: Answer the following position questions.
i. What is the probability that a randomly chosen household has exactly 3 inhabitants?
ii. What is the probability that a randomly chosen household has more than 2 but fewer than 6
inhabitants?

Answer 1

2