Which of the following is true? Forecast errors cannot be negative. Forecast errors are negative when the forecasted rate exceeds the realized rate. Absolute forecast errors are negative when the forecasted rate exceeds the realized rate. None of the above

None of the above.

Step-by-step explanation:

Forecast error is the difference which occurs between the actual observation and a given one over a period of time.

Forecast errors can sometimes be negative, this is due or caused by the difference which arises from the actual and given figures. Forecasting errors help to improve forecasting feedbacks which helps drive better results.

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form