Question

A person with type A blood can donate red blood cells to people with type A or type AB blood. About 31% of the US population has type A blood. University High held a blood drive where 50 students donated blood.
Part A: What is the probability that exactly 17 of the students had type A blood? (5 points)

Part B: What is the probability that at least 17 of the students had type A blood? (5 points)

Answer 1

Answer:

0.107

0.733

Step-by-step explanation:

Part A) Use binomial probability.

P = nCr pʳ qⁿ⁻ʳ

where n is the number of trials,

r is the number of successes,

p is the probability of success,

and q is the probability of failure (1−p).

n = 50, r = 17, p = 0.31, q = 0.69.

P = ₅₀C₁₇ 0.31¹⁷ 0.69⁵⁰⁻¹⁷

P ≈ 0.107

Or, using binompdf function in a calculator:

binompdf(n, p, r)

= binompdf(50, 0.31, 17)

≈ 0.107

Part B) This time, you'll need to use the binomcdf function in a calculator.

binomcdf(n, p, r)

= binomcdf(50, 0.31, 17)

≈ 0.733

Answer 2

Answer:

A. 0.107

B. 0.733

Step-by-step explanation: