Discussion Questions 1. Is the relationship a positive or a negative one? Explain how you can tell and what this means in terms of weight and fuel efficiency. 2. Interpret the slope of the least squares line in terms of weight and fuel efficiency. 3. Predict the fuel efficiency of a vehicle that weighs 4000 pounds. Include units.

Noise and Intelligibility Audiologists study the intelligibility of spoken sentences under different noise levels. Intelligibility, the MRT score, is measured as the percent of a spoken sentence that the listener can decipher at a cesl4ain noise level in decibels (dB). The table shows the results of one such test. (a) Make a scatter plot of the data. (b) Find and graph the regression line. (c) Find the correlation coefficient. Is a linear model appropriate? (d) Use the linear model in put (b) to estimate the intelligibility of a sentence at a 94-dB noise level.