Stat 231 Exam 1 S10 Sol

# Stat 231 Exam 1 S10 Sol - Stat 231 Exam 1 Spring 2010 I...

This preview shows pages 1–4. Sign up to view the full content.

1 Stat 231 Exam 1 Spring 2010 I have neither given nor received unauthorized assistance on this exam. ________________________________________________________ Name Signed Date _________________________________________________________ Name Printed

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 1. A not-so-excellent marksman fires at a solid-circular target of radius 1 ft, and shots hitting the target might be modeled as uniformly distributed inside the circle. If one thinks of the center of the target as the origin of coordinate axes, and , XY as the coordinates of the random location of a hit on the target, a sensible joint pdf for and is 22 1 if 1 , 0 otherwise xy fxy and this is pictured to the right. a) For 0 1 r , what is the probability that a shot hitting the target lands within r feet of the center? (This is PXY r .) b) Find the marginal probability density for X , gx . (Be sure to say completely where any expression you propose for applies.) c) Find the conditional probability density for Y given that 1 2 X . (Again be very careful to say completely where any expression you propose for 1 | 2 hy applies.) 7 pts 7 pts 7 pts
3 2. A lathe turns out cylinders with diameters that are normally distributed with mean 3.02 cm and

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 02/11/2012 for the course STAT 231 taught by Professor Staff during the Fall '08 term at Iowa State.

### Page1 / 6

Stat 231 Exam 1 S10 Sol - Stat 231 Exam 1 Spring 2010 I...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online