By using words per sentence and characters per words, we can create formulas for the Flesch-Kincaid grade level readability. The readability statistics for random pages from a Harry Potter novel are given below.

Words/Sentence 15.7 9 16.3 14.5 9.7 7.4 14 16.1 13.9 12.5 17.2 11.5
Characters/Word 41 4.2 4.2 4.3 4.3 4.2 4.5 4.5 4.3 4 4.4 4.3
F-K Grade Level 5.2 3.7 6.1 4.9 4.4 3.2 5.6 6.9 5.7 4.1 6.7 4.4

What is the correct analysis statement for the coefficient of determination between words per sentence (x-variable) and characters per word (y-variable)?

a. 1.5% of the variance in characters per word is accounted for by words per sentence.
b. 8% of the variance in characters per word is accounted for by words per sentence.
c. 10% of the variance in characters per word is accounted for by words per sentence.
d. 31% of the variance in characters per word is accounted for by words per sentence.
e. None of these