**Unformatted text preview: **Solutions for Practice Test 4 1A. X1(0)= ½; X1(1)=1/6; X2(2)=1/6 X2(1)=1/3; X2(2)=1/2; X2(3)=1/6 1B. E(x1)=1; E(x2)=2 1C. V(X1)= (0
1)^2 (1/2) + (1
1)^2(1/6) + (2
1)^2(1/6) V(x2)= (1
2)^2(1/3) + (2
2)^2(1/2) + (3
2)^2(1/6) 1D. (0
1)(1
2)(1/6) + (0
1)(2
2)(1/3) (I don’t have my calculator so, I will stop here. Just continue this procedure for the rest of it.) 1E.Cov/SDxSDy 1F. No. To make it IND…multiply the marginal’s and put into the respective cells. 1G. [0,2,6] 1H. V= 3^2(V(x1)) 1I. V= 2
4^2(V(X2)) 1J. square root of variance for both 2A. V(x)= 6.64V(Y)= 4.56 2B. Use formula. Z= x + y (sorry for not giving it to you in the practice test. I forgot). V(z)= v(x) + v(y) + 2Cov(xy) 2C. Rho formula 2D. Should be a positive relationship. 3. The squared deviations from the mean. 4. How much two variables deviate together . 5A. mean= 8 *50= 400; SD
72 5B. mean
100/75 SD
100/25 5C. Square the SD’s and then add them. After adding, take square root and divide by 3. 5D. 81
16(25^2) 6. 1 ...

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- Fall '10
- RajendraM.Patel
- the00, =00