Assignment 26

Question 1-4 are about confidence intervals on p. These confidence intervals are exactly like confidence intervals for means! Just follow the equation.

Some things to note:
So the equation is:

p-hat +/- z* [ sqrt ((phat*(1-phat))/n)) ]

So we can see that this equation follows what we are used to. P-hat is like x-bar: the sample proportion. We know how to find z*- it hasn't changed! The next portion is just the standard error- just like we are used to!

Keep note though, I said it was the standard error. Can you tell the reason? It's because we are using p-hat, not Po because we do not have hypothesis.

The confidence interval conclusion has not changed. (BE CAREFUL: We aren't talking about the true mean any more! Remember the proper parameter- check question 1 or last assignment for help.)

Question 5: Here's a hint: Whenever the question is "Why can't we" it means CHECK CONDITIONS!!

Question 6: Check out the equation on the right hand side of the equation sheet, in the row right under the heading "proportions".

Questions 9-12: We will be doing questions 13-16 in class, so these questions will be easier to answer after that!

Good Luck!
-Hillary