There is a simple formula for least squares: you should have been given this and I suggest you look up your notes and see what it is.
The Oregon State Police published data on the total stopping distance for cars traveling at various speeds. The speed is miles per hour and the distance is in feet.
Speed(mph) 'X' 
stopping distance(ft) 'Y' 
(a) Determine the line of best fit (equation of the least-squares line) for these data. Write your answer rounded to nearest thousandths
(b) Draw a scatter diagram and the least-squares line for these data
Like so Vertical side is stopping distance by (25ft)
and Horizontal line is speed by (5mph)
(c) Use the equation in a) to predict the stopping distance for speed of 75mph
(d) How fast was a car traveling when the stopping distance was 362 ft?
Please give details on how you solved TY!