This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 2 (1) (7) The joint mass function for random variables X and Y is in the following table: p(x,y) X= 5 X=5 X=10 Y=10 . 05 . 15 . 2 Y=20 . 15 . 10 . 35 (a) (1) Compute the marginal mass functions p X ( x ) and p Y ( y ) (b) (2) Compute E ( X ) and V ( X ) (c) (2) Compute E ( Y ) and V ( Y ) (d) (1) Compute Cov ( X, Y ) (e) (1) Compute Corr ( X, Y ) 3 (2) (6) Assume the temperature in July across the country follow a Normal distribution with mean 80 o F and variance 25. (a) (1) Whats the probability a randomly selected countys July temperature is between 85 o F and 100 o F? (b) (1) Whats the probability a randomly selected countys July temperature is between 70 o F and 90 o F? (c) (1.5) If a researcher plans to randomly sample 16 counties, whats the probability that average July temperature of the 16 counties is between 76 . 5 o F and 81 . 5 o F? (d) (1.5) Later 16 counties have been randomly selected and their July temperatures measured. The average temperature is 78 . 6 o...
View
Full
Document
 Spring '08
 Staff

Click to edit the document details