Based on the scatterplot, what is the best prediction of the amount of $ in sales when the temperature is at 21°C?

Answer:
Between 400$ and 500$
Step-by-step explanation:
Draw a straight line that follows the scatterplot - either by guesstimating (best choice) or by applying any known method to extrapolate a line. Then it's just a matter of reading the y value corresponding to that x. Hardly a perfect image, but close enough since it's a prediction