If the function y = xa - 31 is a linear function, what is the value of a? 1 2 3 4

A reader of a book wants to estimate the mean word length in the book they are currently reading. They randomly select 19 pages from the book and count the length of 5 words they randomly selected on each of those pages. The table shows the results from the survey.

Using the sample results estimate the mean word length of any word in the book. A) 5.22 letters B) 5.49 letters C) 27.47 letters D) 522 letters