Question

PLEASE HELP fan and medal...
2% of skiers get injured going down a certain hill.
1.What is the probability that exactly 3 of the hundred skiers will injure themselves?

Answer 1

p(exactly 0) = .98^100
p(exactly 1) = 100 * .98^99 * .02
p(exactly 2) = 100*99/2 * .98^98 * .02^2
p(exactly3) = ?? What say you?

Answer 2

.126?

Answer 3

@tkhunny would it be .126?

Answer 4

You tell me. How did you get that?

Answer 5

@tkhunny well i was a little confused, but i skipped to the third equation and plugged that into my calculator

Answer 6

p(0) = 0.133
p(1) = 0.271
p(2) = 0.273
p(3) = 0.182 = \(\dfrac{100*99*98}{3*2}\cdot0.98^{97}\cdot 0.02^3\)

Looks like you're a little off.

You will need to know this rule for your exam. Sometimes, it's convenient just to build the entire distribution. Other times, like this one, don't do that.

Answer 7

.182, thanks! @tkhunny