Word problem based on linear equation..I get the idea but my answer is still not correct

Question

A clothing business finds there is a linear relationship between the number of shirts,,it can sell and the price,, it can charge per shirt. In particular, historical data shows that  shirts can be sold at a price of , while  shirts can be sold at a price of . Give a linear equation in the form  that gives the price  they can charge for shirts. 

Answer 1

Omit the the zeros, i.e. work in thousands of shirt

(16 - 33)/(55 - 4) = -1/3 = (n-33) / (p-4) => p = -3n + 103

This problem is simply asking you to compute the equation of a straight line through the points (55,16) and (33,4). The left side of the equation above is simply the slope of the line.