- #1

GeoMike

- 67

- 0

Ok, this seems like an easy enough problem, but I'm stumped...

----------------------------------------------------------------------

If a motorcycle driver is selected at random from the US population, the probability of that driver being a male is 0.95

If 20 motorcycle drivers are selected at random from the population, what is the probability that

----------------------------------------------------------------------

I've got that the chance of selecting a female is 1/20. And because the population is so large I can treat the events as independent.

I can easily find the probability of selecting 8 women in a row. What's throwing me off is the fact that there are 20 selections, so I know that the probability of selecting 8 total isn't going to be the same as selecting 8 in a row. I can't figure out how to account for the fact that 20 selections increases the probability of 8 women being selected.

I'm also thrown off by the at least 8 vs. exactly 8 part of the problem.

Any hints would be great. Thanks!

-GeoMike-

----------------------------------------------------------------------

If a motorcycle driver is selected at random from the US population, the probability of that driver being a male is 0.95

If 20 motorcycle drivers are selected at random from the population, what is the probability that

*exactly*8 will be women? What is the probability that*at least*8 will be women?----------------------------------------------------------------------

I've got that the chance of selecting a female is 1/20. And because the population is so large I can treat the events as independent.

I can easily find the probability of selecting 8 women in a row. What's throwing me off is the fact that there are 20 selections, so I know that the probability of selecting 8 total isn't going to be the same as selecting 8 in a row. I can't figure out how to account for the fact that 20 selections increases the probability of 8 women being selected.

I'm also thrown off by the at least 8 vs. exactly 8 part of the problem.

Any hints would be great. Thanks!

-GeoMike-

Last edited: