Answer:
See Explanation
Step-by-step explanation:
This question is incomplete, as the required scatter plot is not included in the question. I will answer your question with the attached plot.
Solving (a): The equation
Pick any [tex]two[/tex] [tex]points[/tex]on the [tex]trend[/tex] line
[tex](x_1,y_1) = (30,40)[/tex]
[tex](x_2,y_2) = (80,70)[/tex]
[tex]y = 0.6x + 22[/tex]
Calculate the slope (m)
[tex]m = \frac{y_2 - y_1}{x_2 -x_1}[/tex]
[tex]m = \frac{70 - 40}{80-30}[/tex]
[tex]m = \frac{30}{50}[/tex]
[tex]m = 0.6[/tex]
The equation is then calculated as:
[tex]y = m(x - x_1) + y_1[/tex]
This gives:
[tex]y = 0.6(x - 30) + 40[/tex]
[tex]y = 0.6x - 18 + 40[/tex]
[tex]y = 0.6x + 22[/tex]
Solving (b): y, when [tex]x = 21[/tex]
[tex]y = 0.6x + 22[/tex]
Substitute [tex]x = 21[/tex]
[tex]y = 0.6 * 21 + 22[/tex]
[tex]y = 12.6 + 22[/tex]
[tex]y = 34.6[/tex]
Solving (c): x when [tex]y=150[/tex]
[tex]y = 0.6x + 22[/tex]
Substitute [tex]y=150[/tex]
[tex]150 = 0.6x + 22[/tex]
Collect like terms
[tex]0.6x = 150 -22[/tex]
[tex]0.6x = 128[/tex]
Solve for x
[tex]x = \frac{128}{0.6}[/tex]
[tex]x = 213.3[/tex]
