SAT Question d0430601: Two-variable Data Models And Scatterplots answer and explanation with Desmos solution

The number of people predicted to visit the beach each day is represented by the $y$-values of the line of best fit, and the average temperature, in degrees Celsius (${}^{\circ }$C), is represented by the $x$-values. Since the slope of the line of best fit is approximately $57$, the $y$-value, or the number of people predicted to visit the beach each day, increases by $57$ for every $x$-value increase of $1$, or every $1^{\circ }$C increase in average temperature. Therefore, an increase of $5^{\circ }$C in average temperature corresponds to a $y$-value increase of $57\times 5=285$ additional people per day predicted to visit the beach.