Expectation, variance and transformations

STA 112. Practice questions, not past papers.

Lessons

• Compute moments
• Transform and combine variables

Practice questions

1. Which expression gives variance from raw moments?

   Statistics study edition practice item Q085; Source: T52-55, S15-17, S21-26

2. If Y=a+bX, Var(Y) is what?

   Statistics study edition practice item Q086; Source: T52-55, S15-17, S21-26

3. For independent X and Y, Var(X-Y) equals what?

   Statistics study edition practice item Q087; Source: T52-55, S15-17, S21-26

4. Which statement about expectation is correct?

   Statistics study edition practice item Q088; Source: T52-55, S15-17, S21-26

5. E(X)=3, Var(X)=1. If Y=4+(3)X, find E(Y). Give the value to 4 decimal places.

   Statistics study edition practice item Q089; Source: T52-54, S16-17

6. E(X)=3, Var(X)=1. If Y=4+(3)X, find Var(Y). Give the value to 4 decimal places.

   Statistics study edition practice item Q090; Source: T52-54, S16-17

7. E(X)=5, Var(X)=4. If Y=10+(-2)X, find E(Y). Give the value to 4 decimal places.

   Statistics study edition practice item Q091; Source: T52-54, S16-17

8. E(X)=5, Var(X)=4. If Y=10+(-2)X, find Var(Y). Give the value to 4 decimal places.

   Statistics study edition practice item Q092; Source: T52-54, S16-17

9. E(X)=2, Var(X)=3. If Y=0+(5)X, find E(Y). Give the value to 4 decimal places.

   Statistics study edition practice item Q093; Source: T52-54, S16-17

10. E(X)=2, Var(X)=3. If Y=0+(5)X, find Var(Y). Give the value to 4 decimal places.

    Statistics study edition practice item Q094; Source: T52-54, S16-17

Topic gap report