The scatter plot shows the average monthly temperature, $x,$ and a family's monthly heating cost, $y,$ for $23$ different months.

$($a$)$ Write an approximate equation of the line of best fit for the data. It doesn't have to be the exact line of best fit.

$($b$)$ Using your equation from part $($a$),$ predict the monthly heating cost for a month with an average temperature of $35F.$

Note that you can use the graphing tools to help you approximate the line.