Chapter 3.4, Problem 14E

Remainder Round all answers to two decimal places unless otherwise indicated.

Driving You are driving on a highway. The following table gives your speed $S$, in miles per hour, as a function of the time $t$, in seconds, since you started making your observations.

Time $\mathit{t}$	0	15	30	45	60
Speed $\mathit{S}$	54	59	63	66	68

a. Find the equation of the regression that expresses $S$ as a linear function of $t$.

b. Explain in practical terms the meaning of the slope of the regression line.

c. On the basis of the regression line model, when do you predict that your speed will reach 70 miles per hour? (Round your answer to the nearest second.)

d. Plot the data points and the regression line.

e. Use your plot in part d to answer the following: Is your prediction in part c likely to give a time earlier or later than the actual time when y our speed reaches 70 miles per hour?