Answer:
A) 0.072 = 7.2%
B) 8.3333 at-bats (8 to 9 at-bats)
Step-by-step explanation:
A)
If the chance of hitting a home run is 0.12, the chance of not hitting a home run is 1 - 0.12 = 0.88.
To find the probability of the next home run being in the fifth strike, we need the four other strikes to not be a home run, so the probability is:
P = (0.88)^4 * 0.12 = 0.072 = 7.2%
B)
To find the expected number of at-bats until the next home run, we just need to divide 100% by the probability of hitting a home run (0.12 = 12%):
100/12 = 8.3333
So the expected number is 8 to 9 at-bats