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: STAT350 Final Spring 2007 (12 pts) 1. Multiple choice. No work needs to be shown here, you will not receive partial credit. (i) Correlation coefficient r between two variables x and y has the same meaning as the regression slope between x and y . (a) True (b) False (c) Insufficient information (d) Depends on data (ii) Given a sample, a regression line is fitted, for the fitted line y = a + bx , which of the following is true: (a) The line passes through the point (0 , 0) (b) The line passes through the point ( x, y ) (c) The line passes through (0 , a ) (d) None of the above (iii) Two events A and B , we know that P ( A ) = a , P ( B ) = b , P ( A B ) = c , then 1 ( a + b c ) is the probability of what event? (a) A B (b) A B c (c) A c B c (d) A c B (iv) Let x be the mean of a sample x 1 , x 2 , ..., x n , and let s be the standard deviation. Then what is the mean and standard deviation of x 1 + c, x 2 + c, ...., x n + c ? (a) x + c and s (b) x + c and s + c (c) x and s (d) x and s + c (8 pts) 2. For a continuous random variable x ( &lt; x &lt; ), we know that its density function is f ( x ). Denote the mean of x by x , now show that the variance of x is 1 integraltext  x 2 f ( x ) dx 2 x ....
View Full
Document
 Fall '08
 Staff
 Statistics, Correlation

Click to edit the document details