Question

Marni recorded the cost of different weights of apples and made a scatter plot of her data!

Answer 1

Given:

The scatter plot and trend line.

To find:

Type of association, slope, equation of trend line and average cost of apple per pound.

Solution:

Form the given graph it is clear that the trend line passes through the two points (0,0) and (12,24).

Slope of trend line is

$m=\dfrac{24-0}{12-0}$

$m=\dfrac{24}{12}$

$m=2$

Slope of trend line is positive. It means, it represents positive correlation.

So, the type of association of the scatter plot is positive association.

Therefore, the slope of trend line is 2.

The trend line passes through (0,0) have slope 2, so the equation of the trend line is

$y-y_1=m(x-x_1)$

$y-0=2(x-0)$

$y=2x$

Therefore, the equation of trend line is $y=2x$.

Slope of the line is 2.

Therefore, the average cost of apples per pound is $2.