olor-blindness is any abnormality of the color vision system that causes a person to see colors differently than most people, or to have difficulty distinguishing among certain colors (www.visionrx.com).

Color-blindness is gender-based, with the majority of sufferers being males.

Roughly 8% of white males have some form of colorblindness, while the incidence among white females is only 1%.

A random sample of 20 white males and 40 white females was chosen.

LetXbe the number of males (out of the 20) who are color-blind.

LetYbe the number of females (out of the 40) who are color-blind.

LetZbe the total number of color-blind individuals in the sample (males and females together).

Question 1 of 3

Which of the following is true about the random variables X, Y, and Z?

X is binomial with n = 20 and p = .08.

Y is binomial with n = 40 and p = .01.

Z is not binomial.

All of the above are true.

Only (A) and (B) are true.

Question 2 of 3

What is the probability that exactly 2 of the 20 males are color-blind? (Note: Some answers are rounded.)

.08

.2711

.0143

.5422

.0159

Question 3 of 3

What is the mean and standard deviation of the random variable Y (the number of females out of 40 who are color blind)? Answers may be rounded.

mean= 40, standard deviation=.01

mean =.01, standard deviation = 40

mean =0.4, standard deviation = .629

mean = 0.4, standard deviation = .396

We cannot find the mean and standard deviation since the probability distribution table is not given.