analyzing regression results\nlatasha was presented with the following data set and argued that there was no…

analyzing regression results\nlatasha was presented with the following data set and argued that there was no correlation between x and y. is latasha correct? use the regression equation to explain your reasoning.\n| x | 1 | 2 | 3 | 4 | 5 | 6 | 7 |\n| y | 4 | 5 | 4 | 5 | 4 | 5 | 4 |
Answer
Explanation:
Step1: Calculate the means of x and y
$\bar{x}=\frac{1 + 2+3+4+5+6+7}{7}=\frac{28}{7} = 4$ $\bar{y}=\frac{4 + 5+4+5+4+5+4}{7}=\frac{31}{7}\approx4.43$
Step2: Calculate the slope (b) of the regression line
$b=\frac{\sum_{i = 1}^{n}(x_{i}-\bar{x})(y_{i}-\bar{y})}{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}}$ $(x_1-\bar{x})(y_1 - \bar{y})=(1 - 4)(4-\frac{31}{7})=(- 3)\times(4-\frac{31}{7})=(-3)\times\frac{28 - 31}{7}=\frac{9}{7}$ $(x_2-\bar{x})(y_2 - \bar{y})=(2 - 4)(5-\frac{31}{7})=(-2)\times\frac{35 - 31}{7}=-\frac{8}{7}$ $(x_3-\bar{x})(y_3 - \bar{y})=(3 - 4)(4-\frac{31}{7})=(-1)\times\frac{28 - 31}{7}=\frac{3}{7}$ $(x_4-\bar{x})(y_4 - \bar{y})=(4 - 4)(5-\frac{31}{7})=0$ $(x_5-\bar{x})(y_5 - \bar{y})=(5 - 4)(4-\frac{31}{7})=(1)\times\frac{28 - 31}{7}=-\frac{3}{7}$ $(x_6-\bar{x})(y_6 - \bar{y})=(6 - 4)(5-\frac{31}{7})=(2)\times\frac{35 - 31}{7}=\frac{8}{7}$ $(x_7-\bar{x})(y_7 - \bar{y})=(7 - 4)(4-\frac{31}{7})=(3)\times\frac{28 - 31}{7}=-\frac{9}{7}$ $\sum_{i = 1}^{7}(x_{i}-\bar{x})(y_{i}-\bar{y})=\frac{9}{7}-\frac{8}{7}+\frac{3}{7}+0-\frac{3}{7}+\frac{8}{7}-\frac{9}{7}=0$ $(x_1-\bar{x})^2=(1 - 4)^2 = 9$ $(x_2-\bar{x})^2=(2 - 4)^2 = 4$ $(x_3-\bar{x})^2=(3 - 4)^2 = 1$ $(x_4-\bar{x})^2=(4 - 4)^2 = 0$ $(x_5-\bar{x})^2=(5 - 4)^2 = 1$ $(x_6-\bar{x})^2=(6 - 4)^2 = 4$ $(x_7-\bar{x})^2=(7 - 4)^2 = 9$ $\sum_{i = 1}^{7}(x_{i}-\bar{x})^{2}=9 + 4+1+0+1+4+9 = 28$ $b = 0$
Step3: Analyze the result
Since the slope of the regression line $b = 0$, there is no linear - relationship between $x$ and $y$. LaTasha is correct.
Answer:
LaTasha is correct because the slope of the regression line is 0, indicating no linear correlation between x and y.