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A stoplight at the corner of Lincolnway and Duff Avenue is red 20% of the time. For
someone who drives through this stoplight 10 times a week, what is the
probability that they will stop at least three times?
a: .201
b: .771
c: .878
d: .322
3 answers
My stats book wasn't very helpful in the teaching of this. I'm not really sure how to do it, so if you could teach me some EASIER methods, I would greatly appreciate it!
You can use a binomial probability table (which is much easier) or do this by hand with the following formula:
P(x) = (nCx)(p^x)[q^(n-x)]
x = 0, 1, 2
n = 10
p = .2
q = 1 - p = 1 - .2 = .8
Calculate P(0), P(1), and P(2).
Add P(0), P(1), and P(2) probabilities together, than subtract this value from 1. You should have your answer!
I hope this helps.
P(x) = (nCx)(p^x)[q^(n-x)]
x = 0, 1, 2
n = 10
p = .2
q = 1 - p = 1 - .2 = .8
Calculate P(0), P(1), and P(2).
Add P(0), P(1), and P(2) probabilities together, than subtract this value from 1. You should have your answer!
I hope this helps.
Got it! Thanks!!
1 answer