Question

 

Questions 1 - 4 will refer to the following information.

Recent estimates of the distribution of blood types in the U.S. is as follows, where positive and negative refer to the Rhesus (Rh) factor:

O-positive:         38 %
O-negative:       7 %
A-positive:         33 %
A-negative:        6 %
B-positive:          10 %
B-negative:        2 %
AB-positive:       3 %
AB-negative:     1 %

1.  What is the probability (expressed as a percentage) that a person randomly selected from the population

a)  will be Rh-positive? 84 percent probability
b) will NOT be a universal donor type (type O-negative)? 93 percent probability

2. Is blood type qualitative or quantitative variable? Explain. The blood type is a qualitative variable because the data is going to be a word describing the type of blood.  

3. If you draw blood samples from five randomly selected people from this population and determine how many have a given Rh factor,

a) What is the random variable? how many people have a given Rh factor.
b) What is the probability that two of the blood samples will be Rh negative? 0.1835 or 18%.
c) What is the probability that two of the blood samples will be Rh positive? 0.0289 or 2%.  

4.  (20 pt) If you randomly select 20 people from the population and measure Rh factor, what is the probability of each of the possible outcomes?  

a) none are Rh negative: 0.0306 or 3%.
b) three are Rh negative:0.241 or 24%.
c) more than three are Rh negative: 0.401 or 40%.  

Answer 1