A critical study funded by the National Science Foundation with an additional grant from the American
Military Research Administration measured the deliciousness of various foods cooked for exactly 20
minutes in an array of oven times. This was repeated across three different baked items, namely
cookies, bread rolls, and pretzels.
The data set is located at http://www.uwyo.edu/crawford/Datasets/deliciousness.txt
1) Test whether oven temperature affects the deliciousness.
a. What is the p-value?
b. What would you conclude?
2) Now use a model with deliciousness predicted by goods and oventemp.
a.
b.
c.
d.
e.
Write the prediction equation for cookies
Write the prediction equation for bread
Write the prediction equation for pretzels
What is the standard deviation of the residuals for the model?
What do you think of the residual plot?
3) Now use a model with goods, oventemp and goods*oventemp to predict deliciousness.
a.
b.
c.
d.
e.
Write the prediction equation for cookies
Write the prediction equation for bread
Write the prediction equation for pretzels
What is the standard deviation for the model?
What do you think of the residual plot?
4) Using α=0.05 as the hard cutoff for including a term in the model find the simplest prediction
equation (if something is not significant, then set it to zero)
a. Write the prediction equation for cookies
b. Write the prediction equation for bread
c. Write the prediction equation for pretzels
5) If you want to maximize deliciousness (within the range of oven temperatures in the study) what
should you do?
6) For a bake sale I need to bring something with a deliciousness level of 110. What should I do?
Offer 3 possibilities.
7) List at least two questions about the validity of this study that you would want to ask before 144
billion humanitarian dollars are spent by the government based on this research?