The question: A baseball player has a 5% chance to hit a homerun each at bat. If the player is up 4 times, what is the chance he hits 2 or more homeruns. I came up with the answer, but this was a long process. I need a formula. And is there an easier way of counting the possibilities?(adsbygoogle = window.adsbygoogle || []).push({});

I did it like this:

Probability of 0 out of 4 + 1 out of 4 = 1.401875

Probability of 0 out of 4 is (0.95)(0.95)(0.95)(0.95)(1) with 1 possibility

Probability of 1 out of 4 is (0.05)(0.95)(0.95)(0.95)(4) with 4 possibilities so

The other 11 possibly scenarios are 6 to do 2 out of 4, 4 to do 3 out of 4, and 1 to do 1 out of 4, for a total of 16 (4x4) but is there an easier way than counting these?

Thank you!

EDIT: for 'player' :)

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Probability equation

Loading...

**Physics Forums | Science Articles, Homework Help, Discussion**