Howard Allotrope is a data analyst for the East Monmouth Frozen Foods Company. His company uses a bivariate aging model developed years ago to determine when the products they make should be listed as "expired." They test each product for "residual flavor" weekly and discard any product that scores less than 10.000 flavor units. The model presently used is linear. Howard believes that many. if not all, of the products currently made by Monmouth may age differently than the old array of products for which the present model was developed.
On his own, Howard runs a series of tests on Monmouth's products and come up with the following results.
|
Product
|
Linear
|
Parabola
|
Model r2 Growth
|
Exponential
|
PLC Curve
|
|
Green Beans
|
.63
|
.31
|
.45
|
.55
|
.33
|
|
Beef Stew
|
.23
|
.46
|
.33
|
.71
|
.44
|
|
Cream Pie
|
.31
|
.65
|
.23
|
.62
|
.22
|
|
Fish Sticks
|
.26
|
.44
|
.34
|
.66
|
.37
|
a. Which of the models would you use to determine the best choice of expiration date for the green beans? The cream pie? Why would you choose these?
b. If. for practical reasons. you had to choose only one model to use to set the expiration dates, which would it be? (There is no health risk involved. It's a flavor quality thing.) Why would you choose this model?
c. Which of the two variables involved in this project - time or residual flavor - is the independent?. Which is the dependent? Why?