Wednesday!

Almost to our test!

*It turns out my meeting is at 3:30 tomorrow, so I can stay until like 2:50 if you have questions...*

Tonight, please complete the following (and start studying!)
Page 491: 1, 3, 9, 21 (I may add one more tomorrow

Here are the review questions we looked at after school:

Mr. Carofano plans to estimate the true percentage of EHHS underclassmen who plan to take AP Statistics. He takes a sample of 120 underclassmen, and 29 of them plan to take AP Statistics. Based on past data, it is believe that approximately 10% of underclassmen take AP Statistics.


1. Verify that the conditions for inference are satisfied.
2. Calculate the margin of error for this sample (98% confidence).
3. Estimate the true percentage of underclassmen who plan to take AP Stat using a 98% confidence interval.
4. Interpret the meaning of this interval.
5. Explain the meaning of “98% confidence.”
6. How can Mr. Carofano narrow the width of his interval? What would cause the interval to widen?
7. Based on your interval, do you believe the percentage of underclassmen who plan to take AP Stat has risen?
8. Is there significant evidence to suggest that the percentage of underclassmen taking AP Stat is rising? Conduct and appropriate test at the 5% level of significance. (hypotheses, conditions, math, conclusion).
9. Explain the meaning of the p-value, in context.
10. If the percentage of students in AP Statistics has risen, more sections of the course will be offered and another teacher will be hired. If not, there will only be 3 classes offered.
a. Identify the meaning of a Type I and Type II error in context.
b. Identify a consequence of each.
11. The probability of a Type I error is 5%, and the probability of a Type II is 15%. Calculate the power.
12. Explain the meaning of the power of this test, in context.
13. If Mr. Carofano wants a margin of error of only 4%, what sample size should be used (at 98% confidence)?