Researchers asked each child in a sample of 411 school-age children if they were more or less likely to purchase a lottery ticket at a store if lottery tickets were visible on the counter. The percentage that said that they were more likely to purchase a ticket by grade level are as follows (R&J Child Development Consultants, Quebec, 2001):
a. Construct a scatterplot of y = percentage who said they were more likely to purchase and x = grade. Does there appear to be a linear relationship between x and y?
b. Find the equation of the least-squares line.