What is the probability of flipping a coin 85 times and getting tails 40 times or fewer? Round your answer to the nearest tenth of a percent.

A. 99.8%

B. 95.9%

C. 33.2%

D. 0.4%

C. 33.2%

Step-by-step explanation:

Number of trials n = 85

Probability of success p = 0.5

Number of successes r = 40

Use cumulative binomial probability:

P (x ≤ r) = binomcdf (n, p, r)

P (X ≤ 40) = binomcdf (85, 0,5, 40)

P (x ≤ 40) = 0.332