Determine the quarterly seasonal indexes for the warranty service time series described in question 8.

Question 8

The following quarterly data show the number of cameras (in hundreds)
returned to a particular manufacturer for warranty service over the past 5 years.

Use MINITAB to answer the following questions:

(a) Plot this time series with time on the horizontal axis. Let t = 1 be the first quarter 5 years ago.

(b) Find the equation of the least-squares linear trend line that fits this time series. Let t = 1 be the first quarter 5 years ago.

(c) What would be the trend line for the second quarter of the current year—
that is, 2 periods beyond the end of the actual date?

Transcribed Image Text:

Year 5 4 3 2 1 Quarter I .6 .9 1.6 1.3 1.5 II .4 .6 1.8 1.1 1.3 III .3 .5 1.8 1.0 1.1 IV .6 .8 1.6 1.3 1.5