Online Access Free 8007 Practice Test

Two vectors are orthogonal when:

• A.their determinant is zero
• B.one is a scalar multiple of the other
• C.their components are linearly dependent
• D.their scalar product (sum product) is zero

A simple linear regression is based on 100 data points. The total sum of squares is 1.5 and the correlation between the dependent and explanatory variables is 0.5. What is the explained sum of squares?

• A.0.3333
• B.1.125
• C.0.375
• D.0.75

Which of the following can be used to evaluate a regression model?
(i) Magnitude of R2
(ii) Magnitude of TSS (total sum of squares)
(iii) Tests for statistical significance
(iv) Sign and magnitude of each regression parameter

• A.(i), (ii), (iii), and (iv)
• B.(i), (ii), and (iii)
• C.(i) and (iv)
• D.(i), (iii), and (iv)

An indefinite integral of a polynomial function is

• A.none of the above
• B.always increasing
• C.always positive
• D.always less than the function itself

If a time series has to be differenced twice in order to be transformed into a stationary series, the original series is said to be:

• A.non-functional
• B.differential
• C.integrated of order 2
• D.non-linear