Activity #1 - Is It Getting Harder to Pass Statistics?

A college administrator is investigating the claim that it is harder to pass statistics at his college than it used to be. In 1998, the percentages for letter grades were: A = 15% B = 35% C = 25% D = 15% and F = 10%. A sample of n = 300 statistic students' grades from last semester were selected.

Results were as follows:

A	B	C	D	F
25	65	85	40	35

Using the information about previous performance and data from the recent sample, determine whether there is sufficient evidence to conclude that the grading distribution for statistics is significantly different than in the past. Apply the four steps of hypothesis testing using .05 level of statistical significance and calculate effect size.

1. Hypothesis:
   • H₀:

• H₁

1. Using the critical region ( = .05) what is the degrees of freedom (df)?

• df =

1. Using the critical boundary ( = .05) and df you calculated, what is the critical region?

1. Calculations

1. Make a decision. Write in out in APA and what the hypothesis means.

1. Calculate effect size