2's Day HW!

Tonight we need to get some practice with our 2 proportion z intervals (chapter 22)!

Please complete the following in your textbook:

Page 508: 3, 7

• Be detailed/thorough! Do these as you would on the AP exam--that's why I'm only give you two!
• For 3d, consider your order of subtraction and the sign (+/-) of your interval....
• For 7a, consider if there was (random) assignment of treatments--if so, experiment. If not, observational study. And that's what you reference to explain.
• For 7b don't forget the full process--conditions, math, interpret! You will not earn full hw credit if you don't check conditions, show the math, and interpret your interval here.
• For 7c again consider the order of subtraction and sign of your interval....
• Here are the conditions and interpretation for #7b--they aren't in the back of the book....
• Conditions:
• Men were randomly assigned to have surgery or not
• 347 < 10% of all men who have surgery for prostate cancer
• 348 < 10% of all men who don't have surgery for this
• 16>10, 331>10; 31>10, 317>10
• The men were randomly assigned to treatments, so survival rates are independent for each group.
• Interpret:
• We are 95% confident that the true difference in rates of death for the two groups of men falls between 0.006 and 0.080 (Surgery - No) based on this study.   

Today's Class Recap:

• Stamp = compare two pictures
• Ch. 22 Notes:
• Why is it called a 2 proportion z interval?
• When do we use an interval/test?
• How do we create a 2 proportion z interval? (Completed an example in our notes)
• Conditions
• Math
• Why is the interval negative?
• Interpret the interval
• What does this interval actually mean?

Here's the plan leading up to our next test:

• We have one more chapter in this unit about inference for proportions....
• Ch. 22 = Inferences for Differences in Proportions (2 Prop Z Tests and 2 Prop Z Intervals)
• Tuesday/Wednesday (3/19, 3/20): Ch. 20 Notes = 2 prop z-test and 2 prop z-int examples, notes
• Thursday (3/21): Finish ch. 22 notes, one more test/interval example/context
• Friday (3/22): Ch. 22 classwork
• Monday (3/25): Finish ch. 22 and start ch. 23?
• Tuesday (3/26): TEST!
• Test will be...
• Matching vocab for the entire unit
• Some FR and MC (based more heavily on the 2 prop z stuff)