Suppose you are given the following data for Abbott Laboratories sales.

Use MINITAB to do the following:

(a) Use model A from question 26 to estimate the relationship between sales and time (t).

(b) Use model B from question 26 to estimate the relationship among sales, time (t), and the square of time (t²).

Question 26

In order to forecast the value of a variable, we sometimes use a nonlinear trend regression such as

where t = time. Briefly explain why this model may be better than a model such as

Transcribed Image Text:

Year 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 Sales 351.0 403.9 457.5 458.1 521.8 620.4 765.4 940.6 1084.8 1244.9 Year 1978 1978 1980 1981 1982 1983 1984 1985 1986 1987 Sales 1467.6 1683.2 2038.2 2342.5 2602.4 2927.9 3104.0 3360.3 3870.7 4387.9