In a study of low tar cigarettes, five cigarettes from each of three brands were tested to see if the mean amount of tar per cigarette differs among the brands. i. There are 2 degrees of freedom for the numerator.
Ii) There are 12 degrees of freedom for the denominator.
Iii) If the sum of squares for the brands is 0.07, the mean square for brands is 0.035.
A) (i), (ii) and (iii) are all correct statements
B) (i) and (ii) are correct statements, but not (iii).
C) (i) and (iii) are correct statements but not (ii).
D) (ii) and (iii) are correct statements but not (i).
E) All statements are false

Question

Quizplus · Accepted Answer

The degrees of freedom for the numerator are equal to the number of groups minus 1, which is 3 - 1 = 2. The degrees of freedom for the denominator are equal to the total number of observations minus the number of groups, which is 5 * 3 - 3 = 12. The mean square for brands is equal to the sum of squares for brands divided by the degrees of freedom for the numerator, which is 0.07 / 2 = 0.035.

In a Study of Low Tar Cigarettes, Five Cigarettes from Each