# College Smokers

#### racapozzi

##### New Member
Shoplifters

This is a proportion of a sampling distribution from what I can tell:

I have thought and thought on how to finish this problem. I have read my book. I have plugged and chugged different numbers in hopes of "stumbling" upon the solution. All of this with no luck. I've been working on problems similar to this for at least 5 hours tonight and I'm tired and cranky!

Problem 1:
A population consisted of 700 cases involving shoplifters. If a random sample of 325 was taken and in 95 cases the offender was under age 18, in how many of the 700 cases would you say the person involved was under age 18?

Problem 2:
Suppose it is known that 60% of students at a particular college are smokers. A sample of 500 students from the college is selected at random. Approximate the probability that at least 300 of these students are smokers.

I'm coming up with these figures for problem 1 and may be wrong any help is greatly appreciated!

pi = .136
p = .292
n = 325

((pi(1 - pi) / n)^0.5) = 0.019

z = (p - pi) / sigma sub p

I've added the second problem to prove I'm not crazy! Just sleep deprived. Similar problem that I actually meant to post and that is why this thread is titled "College Smokers" sorry for the confusion.

I know this is probably dumbing this down as I'm sure its an easy solution but like I said I'm tired and am about to just give up! Thanks for any/all help in advance

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