Answer:
Part A: Linear relationship
Part B: Using the dividing method
Slope = -3.325
y-intercept is (0, 88.5)
Step-by-step explanation:
Part A
The is an approximately linear relationship between the temperature of his city and the number of chocolate sold
Part B
The line of best fit can be drawn by
1) Plot the data points on the graph
2) Divide the number of data points into two with a vertical dotted line
3) Mark the center of the data on each side of the dividing central line with an a or x
4) Draw a straight line through the x marks that extends to the plot edges
5) The straight line drawn is the line of best fit
The approximate slope is found from points (0, 90) and (20, 20) using the formula for gradient, m, such that we have;
Where:
y₁ = 88
x₁ = 0
y₂ = 22
x₂ = 20
Therefore;
From the graph, the y-intercept is approximately (0, 88.5) while the x intercept is approximately (26.5, 0)