## StClowers one year ago An online site presented this question, “Would the recent norovirus outbreak deter you from taking a cruise?” Among the 34,696 people who responded, 66% answered “yes”. Use the sample data to construct a 95% confidence interval estimate for the proportion of the population of all people who would respond “yes” to that question. __ < p < __ (round to three decimal places as needed) Does the confidence interval provide a good estimate of the population proportions? (a) No, the sample is a voluntary sample and might not be representative of the population. (b) No, the responses are not independent. (c) Yes, the sample is large enough to provide a good estimate of the population proportion. (d) Yes, all the assumptions for a confidence interval are satisfied.

1. StClowers

2. violy

We will use the 1-PrpZInt function. We will press the STAT, right arrow key twice. Then, we press ALPHA MATH.

3. violy

We will input the appropriate values for x, n and C-level. Then, we will Calculate.

4. violy

By the way, take note that p hat = x/n.

5. StClowers

ok, which values are which though...thats the confusing part.

6. StClowers

@violy

7. violy

For the p hat, we will take note of the sample proportion given for the people who said yes. can you identify that? For the n, it is the sample size or the number of people who responded.

8. StClowers

yes ok...one sec

9. StClowers

it gave me an error...

10. StClowers

do i put in the 34696 just like that?

11. StClowers

I put x = .66 and n = 34696 then .95 for the c-level and it gave me an error.. :(

12. StClowers

ok so i tried it again and entered just 66 as the x and it gave me (.00144, .00236)..isthat right @violy ?

13. violy

Kindly recheck the value of the x.

14. violy

The 0.66 is for the p hat. If we use the formula p hat =x/n what will we get for the x?

15. StClowers

.001?

16. violy

Oops

17. violy

0.66=x/34696. Solve for x.

18. StClowers

Im so clueless, I guess Im not understanding where to get x

19. violy

We have the 34696 being divided on right side, we will use the opposite operation of division, which is?

20. StClowers

multiply

21. violy

That is correct, so we multiply each side by 34696. Can you try it?

22. StClowers

the left side is 22899.36 and the right side is 1203812416

23. violy

We will round that.

24. StClowers

ok.....in the question it asks to round to three decimal places as needed...

25. StClowers

@violy