Can anyone help with the following:

John thinks he can estimate the monthly cost from the average daily temperature (in degrees Celsius) using the model:

Cost = 65.2 - 3.768TEMP

Below is the residuals plot for his data (showing residuals vs Temp)

a)Interpret the slope of the line of the regression model in this context

b) Interpret the y-intercept of the line of the regression model in this context

c) During the months when the temperature stays around freezing (0 degrees), would you expect cost predictions based on this model to be accurate, too low, or too high? Give full reasons.

d) What heating cost does the model predict for a month that averages -12 degrees Celsius?