based on the data shown below, calculate the regression line (each value to at least two decimal places)\ny…

based on the data shown below, calculate the regression line (each value to at least two decimal places)\ny = x + \n\n| x | y |\n| ---- | ---- |\n| 4 | 50.9 |\n| 5 | 47.9 |\n| 6 | 46.6 |\n| 7 | 42.8 |\n| 8 | 42.7 |\n| 9 | 37.8 |\n| 10 | 36.1 |\n| 11 | 33 |\n| 12 | 32.7 |\n| 13 | 29.8 |\n| 14 | 24.6 |\n| 15 | 25.9 |\n| 16 | 22.8 |\n| 17 | 19.2 |
Answer
Explanation:
Step1: Calculate sums
Let (n = 14). Calculate (\sum_{i = 1}^{n}x_i=4 + 5+\cdots+17=147), (\sum_{i = 1}^{n}y_i=50.9+47.9+\cdots+19.2 = 458.5), (\sum_{i = 1}^{n}x_i^2=4^2 + 5^2+\cdots+17^2=1785), (\sum_{i = 1}^{n}x_iy_i=4\times50.9+5\times47.9+\cdots+17\times19.2 = 4307.3).
Step2: Calculate slope (m)
The formula for the slope (m) of the regression - line (y=mx + b) is (m=\frac{n\sum_{i = 1}^{n}x_iy_i-\sum_{i = 1}^{n}x_i\sum_{i = 1}^{n}y_i}{n\sum_{i = 1}^{n}x_i^2-(\sum_{i = 1}^{n}x_i)^2}). Substitute the values: (n = 14), (\sum_{i = 1}^{n}x_i = 147), (\sum_{i = 1}^{n}y_i = 458.5), (\sum_{i = 1}^{n}x_i^2 = 1785), (\sum_{i = 1}^{n}x_iy_i = 4307.3) into the formula. [ \begin{align*} m&=\frac{14\times4307.3-147\times458.5}{14\times1785 - 147^2}\ &=\frac{60302.2-67399.5}{24990 - 21609}\ &=\frac{-7097.3}{3381}\ &\approx - 2.099 \end{align*} ]
Step3: Calculate intercept (b)
The formula for the intercept (b) is (b=\overline{y}-m\overline{x}), where (\overline{x}=\frac{\sum_{i = 1}^{n}x_i}{n}=\frac{147}{14}=10.5) and (\overline{y}=\frac{\sum_{i = 1}^{n}y_i}{n}=\frac{458.5}{14}\approx32.75). [ \begin{align*} b&=32.75-(-2.099)\times10.5\ &=32.75 + 22.0395\ &\approx54.79 \end{align*} ]
Answer:
(y=-2.10x + 54.79)