**Unformatted text preview: **over 6’ 5” tall? (That is taller than 77”?) (b) The average height for men in the United States is 70” (5’ 10”). If you meet a 21 year old from The Netherlands, what is the probability that he will be shorter than the average American? (c) How tall would you have to be for 90% of 21 year olds in The Netherlands to be shorter than you? 3. The number of hours for which a lightbulb works before it burns out is normally distributed with mean 5000 hours and standard deviation 200 hours. (a) What is the median number of hours for which a lightbulb works before it burns out? (b) What is the probability that a lightbulb burns out in under 4800 hours? (c) Suppose you have a room where you install ﬁve of these lightbulbs at the same time. What is the probability that at exactly one lightbulb burns out before 4800 hours? 1...

View
Full Document

- Summer '08
- Jeyeon
- Econometrics, Normal Distribution, Standard Deviation, Washington State USC