2025年8月国际B卷(易) · 第 12 题

2025年8月国际B卷(易) · 原库模块 2 · Q12 原库参考解析

The scatterplot shows data set A, which consists of the weights y, in pounds, of a Labrador retriever puppy at various ages, x, in months. The equation of a line of best fit for the relationship in data set A can be written as \( y=-5.6+8.8x \), where \( 2\le x\le6 \) .

The puppy was weighed again at 9 months old and weighed 52 pounds. Data set B consists of all the data points in data set A as well as the data point (9, 52). The equation of a line of best fit for data set B can be written as \( y=r+sx \) , where r and s are constants and \( 2\le x\le9 \) . Assuming the equations of the lines of best fit are calculated in the same way, which of the following is the best estimate for the value of s?