Predicting Sales from a Line of Best Fit

Prever Vendas a Partir da Reta de Melhor Ajuste

A café records the daily maximum temperature, in degrees Celsius, and the number of iced coffees sold, on eight days with temperatures from $16$ to $27$. On the scatter graph the points lie close to a straight line, and the line of best fit passes through $(18, 24)$ and $(26, 56)$. Find the equation of the line, use it to predict the sales at a temperature of $22$, and say whether the same line should be used to predict the sales at a temperature of $35$.