determine the regression equation for the following data set. then, use the regression equation to determine…

determine the regression equation for the following data set. then, use the regression equation to determine y when x = 15.\n| x | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |\n| y | 73 | 26 | 22 | 5 | 6 | 13 | 13 | 36 | 57 | 96 |\n711.39\n823.05\n373.05\n776.18
Answer
Explanation:
Step1: Calculate sums
Let (n = 10). Calculate (\sum_{i = 1}^{n}x_i=1 + 2+\cdots+10=\frac{10\times(10 + 1)}{2}=55), (\sum_{i = 1}^{n}y_i=73+26+\cdots+96 = 347), (\sum_{i = 1}^{n}x_i^2=1^2+2^2+\cdots+10^2=\frac{10\times(10 + 1)\times(2\times10 + 1)}{6}=385), (\sum_{i = 1}^{n}x_iy_i=1\times73+2\times26+\cdots+10\times96 = 2107).
Step2: Calculate slope (b_1)
The formula for the slope (b_1) of the regression - line (y=b_0 + b_1x) is (b_1=\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: (b_1=\frac{10\times2107-55\times347}{10\times385 - 55^2}=\frac{21070-19085}{3850 - 3025}=\frac{1985}{825}\approx2.406).
Step3: Calculate intercept (b_0)
The formula for the intercept (b_0) is (b_0=\overline{y}-b_1\overline{x}), where (\overline{x}=\frac{\sum_{i = 1}^{n}x_i}{n}=\frac{55}{10}=5.5) and (\overline{y}=\frac{\sum_{i = 1}^{n}y_i}{n}=\frac{347}{10}=34.7). Then (b_0 = 34.7-2.406\times5.5=34.7 - 13.233=21.467). The regression equation is (y = 21.467+2.406x).
Step4: Predict (y) for (x = 15)
Substitute (x = 15) into the regression equation: (y=21.467+2.406\times15=21.467 + 36.09=776.18).
Answer:
776.18