As part of a survey, 118 adults with tattoos were asked whether they got their first tattoo before reaching the age of 25 and whether their first tattoo was done by a professional tattoo artist. The resulting data are summarize
Before the age of 25 25 or older Total
Profetional tatto artist 10 87 97
Not a profetional tatto artist 9 12 21
Total 19 99 118
Which of the following provides evidence that age at first tattoo and whether the first tattoo was done by a professional tattoo artist are not independent for the group of 118 adults with tattoos?
a. 10/97 ≠ 87/97
b. 10/97 ≠ 19/118
c. 10/19 ≠ 10/97
d. 19/118 ≠ 99/118
e. 97/118 ≠ 21/118