What’s the slope of the line ? please help

This is so hard and it’s for a test

The given dot plot represents the average daily temperatures, in degrees fahrenheit, recorded in a town during the first 15 days of september. if the dot plot is converted to a box plot, the first quartile would be drawn at __ , and the third quartile would be drawn at link to the chart is here

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2