View Full Version : elementary statistics course

03-15-2008, 12:45 AM
Hello, again having some difficulties with my chapters... the question asks...

A study was conducted to determine whether remediation in development mathematics enabled students to be more successful in an elementary statistics course. Success here means that a student received the grade of C or better, and remediation was for one year. Following table shows the summary results of the study.

Sample size 100
Number of successes 70

Sample size 40
Number of successes 16

Based on past history, it is known that 75% of the students who enroll in remedial mathematics are successful, whereas only 50% of the non remedial students are successful. What is the probability that the difference in proportion of success for the remedial and non remedial students is at least 10%?

where do I start? what type of formulas are these? thanks sincerely i really appreciate all your time to look at the question


03-15-2008, 04:26 AM
What is this chapter about? The question is confusing in the way it is stated.

03-16-2008, 12:17 PM
the chapter is about the difference in population proportions (p1-p2)
i calculated the sample proportions as:

p hat 1 = x1/n1 = 70/100 = 0.7
p hat 2 = x2/n2 = 16/40 = 0.4

The difference between (p hat 1 - p hat 2) is an unbiased estimator of the differences between the population parameters (p1-p2) so that,
(p hat 1 - p hat 2) = 0.7 - 0.4 = 0.3

...but i dont know how to proceed from here.