No tortilla chip aficionado likes soggy chips, so it is important to find characteristics of the production process that produce chips with an appealing texture. The following data on x
frying time (sec) and y
moisture content (%)

appeared in the article “Thermal and Physical Properties of Tortilla Chips as a Function of Frying Time” (J. of Food Processing and Preservation, 1995: 175–189).

a. Construct a scatter plot of y versus x and comment.

b. Construct a scatter plot of the (ln(x), ln(y)) pairs and comment.

c. What probabilistic relationship between x and y is suggested by the linear pattern in the plot of part (b)?

d. Predict the value of moisture content when frying time is 20 in a way that conveys information about reliability and precision.

e. Analyze the residuals from fitting the simple linear regression model to the transformed data and comment.