A Time Series Is Shown in the Table Below A Plot the Time Series to Determine Which of the

question 35

Essay

A time series is shown in the table below: $$\begin{array} { | c | c | } \hline \text { Time period } & y _ { t } \\\hline 1 & 48 \\2 & 50 \\3 & 46 \\4 & 42 \\5 & 40 \\6 & 32 \\7 & 34 \\8 & 26 \\9 & 21 \\10 & 13 \\\hline\end{array}$$ a. Plot the time series to determine which of the trend models appears to fit better.
b. Use the regression technique to calculate the linear trend line and the quadratic trend line. Which line fits better? Use the best model to forecast the value of y for time period 7.

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Definitions:

Responses

Reactions or actions in answer to a stimulus or situation.

Posttraumatic Stress Disorder

A mental health condition triggered by experiencing or witnessing a terrifying event, characterized by flashbacks, nightmares, and severe anxiety.

Recurrent

Occurring repeatedly or periodically.

Intrusive Thoughts

Unwanted, involuntary thoughts, images, or ideas that can be distressing or disturbing.