Concern over the quality of eyeglasses purchased over the internet led to a study where many glasses were individually ordered from several different online vendors.4 Among the lenses with only antireflective coating, 61 had a thickness at the center greater than 1.9 mm and 31 were thinner. Of the 61 thicker lenses, 12 failed impact testing while 18 of the 31 thinner lenses failed.
(a) Create a cross-classified frequency table with thick/thin lenses and pass/fail as the two traits.
(b) Calculate relative frequencies based on the total number 92.
(c) Comment on any apparent pattern in the relative frequencies and what it means to this problem.