## anonymous one year ago Carl conducted an experiment to determine if there is a difference in the mean body temperature between men and women. He found that the mean body temperature for a sample of 100 men was 91.1 with a population standard deviation of 0.52 and the mean body temperature for a sample of 100 women was 97.6 with a population standard deviation of 0.45. Assuming the population of body temperatures for men and women is normally distributed, calculate the 98% confidence interval and the margin of error for the mean body temperature for both men and women.

1. anonymous

I understand that the z-score formula needs to be used I'm just not sure exactly how to use it

2. nincompoop

|dw:1439414198837:dw|

3. anonymous

x is the 1.5?

4. nincompoop

no I am just showing you graphically how the problem is interpreted in the graph for a normally distributed curve

5. anonymous

Ohhh, okay

6. anonymous

I know the formula is z = (x - 91.1)/(.52) but I don't know how to go from there

7. nincompoop

$$\large \bar x \pm Z \frac{\sigma }{\sqrt{n}}$$

8. anonymous

Whs is x? The probability?

9. anonymous

What*

10. nincompoop

:( x bar is your mean remember?

11. nincompoop
12. nincompoop

we based it off sample mean since we do not have the population mean $$\mu$$

13. nincompoop

14. anonymous

Z-score for a 98% confidence interval is 2.33 right?

15. nincompoop

I didn't solve it, how did you get that ?

16. nincompoop

common value?

17. anonymous

In my notes, I copied down a list of the different scores. Yeah, a common value

18. nincompoop

oaky then use the rest of the formula to get the confidence interval and error

19. nincompoop

|dw:1439415558976:dw|

20. nincompoop

|dw:1439415585464:dw|

21. anonymous

90.9784 91.22116

22. anonymous

isn't .52/10 is .052

23. nincompoop

true haha

24. anonymous

$97.6\pm2.33\times\frac{ .45 }{ \sqrt{100} }$

25. anonymous

And that's for women?

26. anonymous

97.49515 = 97.5 97.70485 = 97.7

27. nincompoop

correct

28. anonymous

So those were the confidence intervals?

29. nincompoop

correct

30. anonymous

So then what's the margin of error?

31. nincompoop

you use almost the same formula but without the sample mean

32. anonymous

I'm sorry if I'm being difficult, I'm studying for my final and this is the only section I didn't understand

33. anonymous

So the margin of error is .12116 for men and .10485 for women?

34. anonymous

Thank you so much for your help, I think I actually get it now :))

35. nincompoop

btw, what book do you use for statistics?

36. anonymous

I'm in Algebra 2 Honors, Statistics is just a couple chapters we cover

37. nincompoop

ah

38. nincompoop

if you want a book, which I think you are going to need let me know you will retake this in college again and you should even though you took AP or honors because it is a little more in-depth quite intense.

39. anonymous

I'm taking Calc and AP Stats next year so if you have any suggestions for books that'd be great

40. anonymous

Please let me know when you have it so I can delete it off of here :)

41. nincompoop

k

42. nincompoop

43. anonymous

Thank you so much! :)

44. nincompoop

if for some reason you want to use the DVD or video lectures and have difficulty playing them, use MPlayerX program, you won't need to worry about codex or anything to use it and can play almost every video file format known to mankind.

45. anonymous

I will probs only use the book, but thank you for everything :)

46. anonymous

@nincompoop it says I need to rate you or you don't get your "rewards" and that there should be a bell moving around but there is no bell

47. nincompoop

There is no need to rate me, I am more concerned with you understanding the subject matter. Let us skip that portion for now and try again next time.

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