*! 20 **

meg plotted the graph below to show the relationship between the temperature of her city and the number of sweaters sold at a store:

main title on the graph is sweater sale.
graph shows 0 to 30 on x axis at increments of 5 and 0 to 12 on y axis at increments of 1. the label on the x axis is temperature in degree c, and the label on the y axis is number of sweaters sold. dots are made at the ordered pairs 0, 12 and 2.5, 10 and 2.5, 11 and 5, 10 and 7.5, 9 and 7.5, 10 and 10, 7 and 12.5, 6 and 12.5, 8 and 15, 4 and 15, 7 and 17.5, 5 and 20, 1 and 20, 3 and 22.5, 9 and 25, 1 and 27.5, 1.

write the approximate slope and y-intercept of the line of best fit. show your work, including the points that you use to calculate slope and y-intercept

Hello!

Lets start easy off like this:

When the temperature in *C is higher there are less sweaters bought.

So as the temperature goes up, the amount of sweaters sold goes down this means we have a negative correlation, negative correlation means one variable goes up and the other goes down (or vice versa) positive correlation means both variables go up together or go down together

Positive is when they go up together or down together.

Now...what two points lie on that blue line?

(5,10) and (0,12)

What is the slope of the line through (5,10) and (0,12)? 

Slope formula: m=y2−y1x2−x1

Subtract the y values subtract the x values (same order) divide the differences.

(5,10) and (0,12)
subtract the y values
12 - 10 = 2

subtract the x values (same order)
0 - 5 = -5

Divide the differences
ydiff/xdiff = 2/(-5) = -2/5 = -0.4

The slope is m = -0.4

The slope is negative since we go downhill as we move from left to right.

The y intercept 12

So its y=-0.4x+12


I think that's it.

Hope this Helps! Have A Wonderful Day! :)