I am preparing for a chapter test in my prob/stat class and since my teacher no longer cares about our class and the textbook is as confusing as a foriegn languaga, i am in need of help. i am trying to review an old quiz ao here is one of the questions.

Question

the probability that a costomer selects 1,2,3,4 or 5 items at a convenience store are 3.02,.012,.023,.018 and.015, respectively.

find P(X>3.5)
find P(X<5)

Answer 1

I think there's a mistake with the probabilities were given. 1) probabilities can't be >1 (you get greater than 100% chance). 2) the probabilities don't add up to 1

here is what I think they should be:
.32, .12, .23, .18, .15

P(x>3.5) = probability that a customer selects more than 3.5 items = p(4) + p(5) = .18 + .15

you can do the other one by yourself.

Answer 2

23