What is the coefficient of 15ab 1/3

Polynomial that can be factored as (3x-4)(3x+4)

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

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.