Consider the calculator sales in Table 6.2 and Figure 6.4 of Chapter 6.

a. find the initial values l₀ and b₀ by using Excel or some other statistical package to fit a straight line to the first half of the data.

b. Set up an Excel spreadsheet to perform Holt's trend corrected exponential smoothing.

c. Use Solver to find the values of?? that minimize the SSE.

d. Find point forecasts and 95% prediction intervals for January, February, and March of year 3.

Table 6.2 Calculator Sales Data

Month	Year 1	Year 2
January	197	296
February	211	276
March	203	305
April	247	308
May	239	356
June	269	393
July	308	363
August	262	386
September	258	443
October	256	308
November	261	358
December	288	384

FIGURE 6.4 450 JMP IN plot of E calculator sales 400 versus time 350 (months) 300 Calculator sales 250 200 150 0 15 20 25 UT 10 Time