Sign In
Recall the Slope Formula.
The y-values of the graph are estimated values, so approximate the x-value when the y-value is $169.47.
$ 63.24
4 children
The graph shows the relationship between the number of children and the amount of money spent on groceries.
y= 21.08x+ 85.15 In this equation, 21.08 is the slope and 85.15 is the y-intercept of the line. Now remember that we can find the slope by dividing the vertical distance of two points by the horizontal distance of these two points. Slope=Vertical distance/Horizontal distance We are looking for the vertical distance, since we want to find the difference in the amount spent on groceries for a family with five children and a family with two children.
Substitute values
LHS * 3=RHS* 3
a/3* 3 = a
Multiply
Rearrange equation
The estimated number of children in a family that spends $169.47 on groceries per week is 4.
