Which method in time series analysis involves using past observations to predict future values, often denoted as "Y-hat"?

What is the primary characteristic of a time series data set?

A. Random data

B. Data points are not related

C. Data is collected at irregular intervals

D. Data is collected over time

In time series analysis, what is the term for the repeating patterns that occur at regular intervals?

A. Outliers

B. Trends

C. Seasonality

D. Noise

Which type of time series data is characterized by a consistent upward or downward movement over time?

A. Stationary

B. Seasonal

C. Trend

D. White noise

What is the primary goal of "detrending" in time series analysis?

A. To remove seasonality from the data

B. To remove outliers from the data

C. To identify trends in the data

D. To add noise to the data