Over the years grades in an introductory statistics course were recorded and showed the following proportions:
A = 0.20 B = 0.30 C = 0.30 D = 0.10 and F = 0.10
This year there were 200 students in the introductory statistics class and they received the following grades
A = 56 B = 74 C = 60 D = 9 and F =1
We are interested in knowing if the distribution of grades this year is the same as in the past. The plan is to use a X2 statistic. The X2 statistic has appromimately a chi-square distribution. How many degrees of freedom does this distribution have?