The quarterly sales ($millions) of a department store chain were recorded for the years 1995-1998. $$\begin{array} { | c | c c | }
\hline \text { Year } & \text { Quarter } & \text { Sales } \
\hline 1995 & 1 & 21 \
& 2 & 36 \
& 3 & 28 \
& 4 & 44 \
1996 & 1 & 25 \
& 2 & 23 \
& 3 & 39 \
& 4 & 36 \
1997 & 1 & 30 \
& 2 & 41 \
& 3 & 47 \
& 4 & 55 \
1998 & 1 & 34 \
& 2 & 29 \
& 3 & 32 \
& 4 & 48 \
\hline
\end{array}$$ a. Calculate the four-quarter centred moving averages.
b. Graph time series and moving averages. State your conclusions about time-series smoothing?

Question

The quarterly sales ($millions) of a department store chain were recorded for the years 1995-1998. $$\begin{array} { | c | c c | } 
\hline \text { Year } & \text { Quarter } & \text { Sales } \
\hline 1995 & 1 & 21 \
& 2 & 36 \
& 3 & 28 \
& 4 & 44 \
1996 & 1 & 25 \
& 2 & 23 \
& 3 & 39 \
& 4 & 36 \
1997 & 1 & 30 \
& 2 & 41 \
& 3 & 47 \
& 4 & 55 \
1998 & 1 & 34 \
& 2 & 29 \
& 3 & 32 \
& 4 & 48 \
\hline
\end{array}$$ a. Calculate the four-quarter centred moving averages.
b. Graph time series and moving averages. State your conclusions about time-series smoothing?

Quizplus · Accepted Answer

The Answer of The quarterly sales ($millions) of a department store chain were recorded for the years 1995-1998. $$\begin{array} { | c | c c | } 
\hline \text { Year } & \text { Quarter } & \text { Sales } \
\hline 1995 & 1 & 21 \
& 2 & 36 \
& 3 & 28 \
& 4 & 44 \
1996 & 1 & 25 \
& 2 & 23 \
& 3 & 39 \
& 4 & 36 \
1997 & 1 & 30 \
& 2 & 41 \
& 3 & 47 \
& 4 & 55 \
1998 & 1 & 34 \
& 2 & 29 \
& 3 & 32 \
& 4 & 48 \
\hline
\end{array}$$ a. Calculate the four-quarter centred moving averages.
b. Graph time series and moving averages. State your conclusions about time-series smoothing?

The Quarterly Sales ($Millions) of a Department Store Chain Were