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Return-fit residual and score practice

These original questions distinguish a residual from a forecast or skill conclusion.

Use the original fitted equation

The original line is fitted asset return=1.2%+2.1×benchmark return. SSE=1.2 and Syy=45.3 in percentage points squared, with five observations.

Retain the descriptive task

The questions calculate supplied fitting quantities. No significance test, future-return probability or official question source is implied.

Try the questions

At benchmark 1% and observed asset 2.5%, what is the residual?

  • A.

    −0.8 percentage points

  • B.

    +0.8 percentage points

  • C.

    1.5 percentage points

Answer and explanation

Answer: A

A residual subtracts the fitted line, not a unit benchmark return.

A

Fitted return is 3.3%, and observed minus fitted is −0.8.

B

This reverses the defined residual sign.

C

This is asset minus benchmark, not the fitted residual.

What is the residual standard-error calculation?

  • A.

    √(1.2/3)

  • B.

    √(1.2/4)

  • C.

    1.2/3

Answer and explanation

Answer: A

Take the square root after the appropriate squared-sum division.

A

Two fitted coefficients leave n−2=3 residual degrees of freedom.

B

This is sample dispersion of these residuals, a different divisor.

C

This remains on the squared-return scale.

If asset returns are constant and the benchmark varies, what does this tool report?

  • A.

    Slope zero and a defined intercept; correlation/R² omitted as undefined

  • B.

    R² 100% by definition

  • C.

    No intercept can be estimated

Answer and explanation

Answer: A

A constant fit and a defined variation ratio are different questions.

A

The response dispersion denominators vanish.

B

That invents an explained-variation ratio at 0/0.

C

The varying benchmark still identifies the straight line.

Further references