#### stat84

##### New Member
I've been looking over some problems to see what tests and techniques i need to use but it's been a long while since i've worked on statistics, so could someone please help me. I don't need you to answer the quesions, just advise me as to the tests and formulas needed to solve it.
Q1: The psychology dept. at a certain college claims that the grades in its introductory course are distributed as follows: 10% A’s, 20% B's, 40% C's, 20% D's, and 10% F's. In a poll of 200 randomly selected students who had completed this course, it was found that 16 had received A's, 43 B's, 65 C's, 48 D's, and 28 F's. Does this sample contradict the department's claim at the 0.05 level?

Q2: A fire insurance company decided that the mean distance from home to the nearest fire department in a suburb of Chicago was at least 4.7 miles. Members of the community set out to show that the mean distance was less than 4.7 miles. They randomly identified 64 homes and measured the distance to the nearest fire department. The resulting sample mean was 4.4 miles and the standard deviation 2.4 miles. Based on this sample, is the distance less then 4.7 miles, at the 0.01 level?

I know it seems easy but I'm having trouble with it. I have some ideas about what tests to use but i'm not sure.

#### PeterVincent

##### New Member
Q1 do a chi squared test. Form the expected values for results. Get sum of (expected - observed)^2/expected; degrees of freedom = 4

Q2.
Do a z test

Peter