From the scatter plot of sales of Ceiling Fan in relation to Temperature.
(a) We are asked to characterized the money spent on Ceiling Fan to Temperature.
The relationship between the money spent on Ceiling Fan and Temperature is positive correlation.
When the y variable tends to increase as the x variable increases, we say there is a positive correlation. Which we can see in the scatter plot in the question.
(b) using the function y = 20x + 0, we are to find the predicted amount of sales if temperature is 21 degrees Celsius.
With the function:
y = 20x + 0
When Temperature is 21 degrees that means x = 21
So let's input x = 21 into the given function.
y = 20(21) + 0
y = 420 + 0
y = 420
Therefore, the predicted amount of sales when Temperature is 21 degrees Celsius is $420.
(c) What does the number 0 in the function mean in the contest of this situation?
In a linear interpretation which the function represents, the number 0 can be seen as the y intercepts of the function.