A school district administrator suspected that a greater proportion of private school teachers are National
Board Certified compared to public school teachers. To test this theory, he randomly sampled private and
public high school teachers in his district and found that among 95 private school teachers 36 were certified,
and out of 206 public school teachers only 68 were certified.
a. Do we have enough evidence that a greater proportion of private
school teachers are certified than public school teachers? Test at the
1% level of significance. You must use the Point Estimate method 1 1 NOTE: Point Estimate method
refers to the use of rejection zones and
a calculated value to reach a decision
towards the null hypothesis.
(8 pts)
b. Find the effect size and give an interpretation. (4 pts)
c. Re-do the test in part (a) but, this time you must use the Confidence Interval
method to make your decision toward the null hypothesis. Do you
reach the same conclusion as before? (8 pts)
d. Write a full conclusion to answer the question: โAre private school
teachers more likely to be board certified than public school teach-
ers?โ. Rely on your work in the previous questions (parts a through
d) to provide certain details about your statistical test. (10 pts)