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# S2 question Sampling Watch

1. Could I have help with 6a please?Attachment 583034583036
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2. (Original post by swagmister)
Attachment 583034583036Could I have help with 6a please?
Unless you've misread the value from the table I see nothing wrong with your working
3. (Original post by SeanFM)
Unless you've misread the value from the table I see nothing wrong with your working
The answers say it's 0.155 I tried 6b which was a similar question but also got the wrong answer
4. (Original post by swagmister)
The answers say it's 0.155 I tried 6b which was a similar question but also got the wrong answer
5. (Original post by SeanFM)
Maybe the textbook is wrong? I'll ask my teacher tomorrow, thanks for taking a look anyway 👍
6. Shouldn't there be a continuity correction, since it's a binomial distribution?

(Original post by swagmister)
Could I have help with 6a please?Attachment 583034583036
7. (Original post by NotNotBatman)
Shouldn't there be a continuity correction, since it's a binomial distribution?
Idk that would make sense but I didn't use it in any of the other questions that similar and got the right answer
8. (Original post by swagmister)
Idk that would make sense but I didn't use it in any of the other questions and got the right answer
Try it again with a continuity correction and see if you get the answer in the textbook.
9. (Original post by NotNotBatman)
Try it again with a continuity correction and see if you get the answer in the textbook.
I got 0.9292
10. (Original post by NotNotBatman)
Try it again with a continuity correction and see if you get the answer in the textbook.
Do you not need a continuity correction because the means and sampling mean aren't discrete?
11. (Original post by swagmister)
I got 0.9292
You'd need to apply the continuity correction to the total score (mean multiplied by number of throws) and then divide by 70.
12. (Original post by NotNotBatman)
You'd need to apply the continuity correction to the total score (mean multiplied by number of throws) and then divide by 70.
So ((35/12)+0.5)/70??
13. (Original post by swagmister)
So ((32/15)+0.5)/70??
Where's 32 and 15 coming from?

You do 3.3 x 70 = 231, then apply the continuity correction and divide by 70, then you find your standardized z value.
14. (Original post by NotNotBatman)
Where's 32 and 15 coming from?

You do 3.3 x 70 = 231, then apply the continuity correction and divide by 70, then you find your standardized z value.
Oh I was taught to add or minus 0.5 onto x where eg. P(X<x), I got 0.1723 this time
15. (Original post by swagmister)
Oh I was taught to add or minus 0.5 onto x where eg. P(X<x), I got 0.1723 this time
In this case it's different because it's a mean.

You've done the continuity correction the wrong way around; it's less than x, not less than or equal to, so subtract 0.5.

230.5/70 = 3.29...
16. (Original post by NotNotBatman)
In this case it's different because it's a mean.

You've done the continuity correction the wrong way around; it's less than x, not less than or equal to, so subtract 0.5.

230.5/70 = 3.29...
Oh right I haven't learnt that yet, oh yeah, I got 0.1585
17. Nevermind I read the tables wrong
18. Got 0.155 now!
19. How come you use the continuity correction in Q6 but not Q5?

(Original post by NotNotBatman)
In this case it's different because it's a mean.

You've done the continuity correction the wrong way around; it's less than x, not less than or equal to, so subtract 0.5.

230.5/70 = 3.29...
20. (Original post by swagmister)
How come you use the continuity correction in Q6 but not Q5?
I'm not sure, I think you should use a continuity correction.

Updated: October 4, 2016
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