5.44 The following data on x 5 frying time (in seconds)

and y 5 moisture content (%) appeared in the paper

“Thermal and Physical Properties of Tortilla Chips as a Function of Frying Time” (Journal of Food Processing and Preservation [1995]: 175 –189):

x 5 10 15 20 25 30 45 60 y 16.3 9.7 8.1 4.2 3.4 2.9 1.9 1.3

a. Construct a scatterplot of the data.

b. Would a straight line provide an effective summary of the relationship?

c. Here are the values of x9 5 log(x) and y9 5 log(y):

x9 0.70 1.00 1.18 1.30 1.40 1.48 1.65 1.78 y9 1.21 0.99 0.91 0.62 0.53 0.46 0.28 0.11 Construct a scatterplot of these transformed data, and comment on the pattern.

d. Based on the accompanying MINITAB output, does the least-squares line effectively summarize the relationship between y9 and x9?

The regression equation is log(moisture) 5 2.02 2 1.05 log(time)

Predictor Coef SE Coef T P Constant 2.01780 0.09584 21.05 0.000 log(time) 21.05171 0.07091 214.83 0.000 S 5 0.0657067 R -Sq 5 97.3% R -Sq(adj) 5 96.9%

Analysis of Variance Source DF SS MS F P Regression 1 0.94978 0.94978 219.99 0.000 Residual Error 6 0.02590 0.00432 Total 7 0.97569

e. Use the MINITAB output to predict moisture content when frying time is 35 sec.