1)A time series is:

a. Synonymous with forecasting.

b. A tool for generating profile plots.

c. A set of observations on a quantitative variable collected over time.

d. A relationship between two variables.

2)The general form of an extrapolation model is:

a. = f(X1, X2, ..., Xk).

b. = f(Y1, Y2, ..., Yk).

c. Y = f(Y1, Y2, ..., Yk).

d. = f(Y1, Y2, ..., Yk).

3)In stationary time series:

a. There is a statistically significant upward trend in the data over time.

b. There is a statistically significant downward trend in the data over time.

c. There is no significant upward or downward trend in the data over time.

d. Seasonality and cycles are statistically significant in the data.

4)Common accuracy measures in modeling time series data include:

a. The mean absolute percent error (MAPE).

b. The root mean square error (RMSE).

c. The mean absolute deviation (MAD).

d. The mean square error (MSE)

e. All of the above are measures of accuracy.

5)After collecting the data for a time series variable, the next step in building a time series model is to:

a. Estimate population parameters.

b. Inspect the data plotted over time.

c. Conduct tests for statistical significance.

d. Calculate sample statistics.