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natash
06-17-2010, 07:50 PM
One statistic used to assess professional golfers is driving accuracy, the percent of drives that land in the fairway.
Driving accuracy for PGA Tour professionals ranges from about 40% to about 75%.
Tiger Woods hits the fairway about 60% of the time.
One reason why the Normal approximation may fail to give accurate estimates of binomial probabilities is that the binomial distributions are discrete and the Normal distributions are continuous.
That is, counts take only whole number values but Normal variables can take any value.
We can improve the Normal approximation by treating each whole number count as if it occupied the interval from 0.5 below the number to 0.5 above the number.
For example, approximate a binomial probability P(X ≥ 10) by finding the Normal probability P(X ≥ 9.5).
Be careful: binomial P(X > 10) is approximated by Normal P(X ≥ 10.5).
We saw in Exercise 13.30 (above) that Tiger Woods hits the fairway in 60% of his drives.
We will assume that his drives are independent and that each has probability 0.6 of hitting the fairway.
Tiger drives 25 times.
The exact binomial probability that he hits 15 or more fairways is 0.5858.

What is the Normal approximation to P(X ≥ 15)?
Do not use the continuity correction.
A. 0.5
B. 0.68
C. 0.95
D. 0.75


What is the Normal approximation using the continuity correction? Use Table A to answer the question.
A. 0.4207
B. 0.1586
C. 0.5793
D. 0.6591

thank you

Dason
06-18-2010, 10:20 AM
Read this (http://www.talkstats.com/showthread.php?t=60)
You clearly just copied your homework problem directly here.

natash
06-18-2010, 04:34 PM
the sky is blue and water is wet, whats ur point?

Dason
06-18-2010, 04:44 PM
My point was that we do usually provide homework help but you need to show some sort of work. Also note that I said "help" and that we don't flat out just give you the answers. It sounds like you didn't read the thread I linked to explaining these policies. I understand that I probably came off as slightly rude but we get a lot of people just posting homework questions while showing no work and expecting us to just give them the answers. My standard response is to link to the thread and tell them my observation that they are just posting homework without showing any work. So until I see some sort of work or explanation as to what you're getting stuck on I'm not going to provide any help.

Link
06-18-2010, 05:05 PM
My point was that we do usually provide homework help but you need to show some sort of work. Also note that I said "help" and that we don't flat out just give you the answers. It sounds like you didn't read the thread I linked to explaining these policies. I understand that I probably came off as slightly rude but we get a lot of people just posting homework questions while showing no work and expecting us to just give them the answers. My standard response is to link to the thread and tell them my observation that they are just posting homework without showing any work. So until I see some sort of work or explanation as to what you're getting stuck on I'm not going to provide any help.

+1 on that. The people here who know what they're doing are pretty nice and more than willing to help you if you're stuck. When it becomes obvious that we're just being used to answer homework questions that you can answer yourself with a little bit of effort, it's slightly offensive.

Now if you show what you've done and where exactly you're stuck, its more likely people will respond.

PS. Don't take offense to Dason's post. He was only trying to help you. Note that I thought the same thing when I first saw your thread and ignored it.