3. The closer to a major holiday, prices on certain goods increases. A teacher wanted to purchase his mother a new series of books for reading. The teacher kept close watch on two online stores and tracked the price on the books for 11 days before the holiday. The scatterplot displays the relationship between price and the days remaining along with the residual plot, the equation of the least-squares regression line and some summary statistics.
y=182.533-5.458 x r=-0.990 r²=0.981
s=2.6
a. Interpret the standard deviation of the residuals.
b. Interpret r 2
c. Interpret the correlation.
d. Is least-squares regression appropriate to model the relationship between days remaining and price? Explain.
e. Does the strength of the correlation mean that there is a cause-and-effect relationship between the days remaining before the holiday and price? Explain.