1 The price of diamond rings. A newspaper advertise- ment in the Straits Times of Singapore contained pictures of diamond rings and listed their prices, diamond weight (in carats), and gold purity. Based on data for only the 20-carat gold ladies' rings in the advertisement, the least- squares regression line for predicting price (in Singapore dollars) from the weight of the diamond (in carats) is 17 = price 259.63 +3721.02 carats (a) What does the slope of this line say about the rela- tionship between price and number of carats? (b) What is the predicted price when number of interpret this price?