Hints for Problem Set 10

Problem 1:
(B) You need to give me an explanation using CORRECT statistical terminology to get full credit. Just writing "Central Limit Theorem," is going to earn you about a 2/10.....

Problem 2:
(A) You will have two x-bars for this question. This question is a bit tricky - my advice is to draw a picture of a Normal Curve and shade the area that you're trying to find. Once you find your answer, ask yourself, "Does this make sense?" You are finding the probability that it will shut down, or NOT work....

(B) I recommend finding what two standard deviations from the mean would be, first, then use those two values to find two separate z-scores. The difference of those two z-scores is your answer.

Problem 3:
This is a tough one because it doesn't explicitly tell you what the means are. Consider the population mean to be the total baggage limit divided by the number of passengers on the flight. It gives you the standard deviation, and suppose your sample mean is represented by the individual passenger.

EARLY CHRISTMAS PRESENT - Skip number four on the problem set. It is worded poorly. Instead of taking paragraphs on paragraphs to explain it, just don't worry about it - Happy Holidays.

Problem 5:
(A) Change p-hat to p. The mean is already given to you (think about what p=0.5 represents...) and standard deviation by doing the square root of p(1-p)/n

(C) Remember that you're looking for the upper part of the curve here, so think about what you would need to do to your probabilities to get the correct answer...

(D) Think about the Central Limit Theorem here, and the computer program that I showed you in class. What happens to the Normal Curve when there are more observations? And because of the way the Normal Curve looks, what then should happen to your probabilities?