Re: E as a % of a standard deviation

2001-11-25 Thread Barry Edwards
Algebraically, E = [z(a/2) / SQRT(n)] x SD, so it must be that the margin of error (maximum error as you called it) is a multiple of the population standard deviation. Keep in mind what these values represent. E is the margin of error of the estimate of mu, the population mean. SD is the

Re: E as a % of a standard deviation

2001-10-02 Thread Magenta
SRS = simple random sample. cheers Michelle Paul Bellamy [EMAIL PROTECTED] wrote in message UD2t7.56886$[EMAIL PROTECTED]">news:UD2t7.56886$[EMAIL PROTECTED]... Thanks alot - what does SRS mean? Also what does frequentist mean - I have also seen that word? Dennis Roberts [EMAIL PROTECTED]

Re: E as a % of a standard deviation

2001-09-30 Thread John Jackson
Donald, I totally agree w/your point about the stratification of the sample. My facts were set up merely for simplicity's sake notwithstanding their clear artificiality. The only instances of multiple samples I have seen are in textbooks to prove the CLT; that w/increasing numbers of sample

Re: E as a % of a standard deviation

2001-09-30 Thread Rich Ulrich
On Sun, 30 Sep 2001 00:34:40 GMT, John Jackson [EMAIL PROTECTED] wrote: Here is my solution using figures which are self-explanatory: Sample Size Determination pi = 50% central area 0.99 confid level= 99%

Re: E as a % of a standard deviation

2001-09-29 Thread John Jackson
Here is my solution using figures which are self-explanatory: Sample Size Determination pi = 50% central area 0.99 confid level= 99% 2 tail area 0.5 sampling error 2% 1

Re: E as a % of a standard deviation

2001-09-29 Thread Donald Burrill
On Sun, 30 Sep 2001, John Jackson wrote: Here is my solution using figures which are self-explanatory: Sample Size Determination pi = 50% central area 0.99 confid level= 99% 2 tail area 0.5 sampling

Re: E as a % of a standard deviation

2001-09-29 Thread Donald Burrill
On Fri, 28 Sep 2001, John Jackson wrote in part: My formula is a rearrangement of the confidence interval formula shown below for ascertaining the maximum error. E = Z(a/2) x SD/SQRT N The issue is you want to solve for N, but you have no standard deviation value.

Re: E as a % of a standard deviation

2001-09-29 Thread John Jackson
Donald - Thank you for your cogent explanation of a concept that is a bit hard to grasp. After researching it more, I determined that there is a gaping hole in my knowldege relating to the area of inferences on a population proportion so I am somethat admittedly in the dark and have to study up a

Re: E as a % of a standard deviation

2001-09-28 Thread John Jackson
your formula is right on the money, but suppose your problem supplies no SD - see my recent message in this thread. Dennis Roberts [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... this is the typical margin of error formula for building a confidence interval were

Re: E as a % of a standard deviation

2001-09-28 Thread John Jackson
Really sorry. My formula is a rearrangement of the confidence interval formula shown below for ascertaining the maximum error. E = Z(a/2) x SD/SQRT N The issue is you want to solve for N, but you have no standard deviation value. The formula then translates into n = (Z(a/2)*SD)/E)^2Note:

Re: E as a % of a standard deviation

2001-09-28 Thread Dennis Roberts
this is the typical margin of error formula for building a confidence interval were the sample mean is desired to be within a certain distance of the population mean n = sample size z = z score from nd that will produce desired confidence level (usually 1.96 for 95% CI) e = margin of error

Re: E as a % of a standard deviation

2001-09-27 Thread Glen Barnett
? What's it a formula for? could you express E as a % of a standard deviation . What's E? The above formula doesn't have a (capital) E. What is Z? n? e? In other words does a .02 error translate into .02/1 standard deviations, assuming you are dealing w/a normal distribution? ? How does thi

Re: E as a % of a standard deviation

2001-09-27 Thread John Jackson
re: the formula: n = (Z?/e)2 This formula hasn't come over at all well. Please note that newsgroups work in ascii. What's it supposed to look like? What's it a formula for? could you express E as a % of a standard deviation . What's E? The above formula doesn't have a (capital) E.

E as a % of a standard deviation

2001-09-26 Thread John Jackson
re: the formula: n = (Z?/e)2 could you express E as a % of a standard deviation . In other words does a .02 error translate into .02/1 standard deviations, assuming you are dealing w/a normal distribution

Re: E as a % of a standard deviation

2001-09-26 Thread Dennis Roberts
At 04:49 PM 9/26/01 +, John Jackson wrote: re: the formula: n = (Z?/e)2 could you express E as a % of a standard deviation . In other words does a .02 error translate into .02/1 standard deviations, assuming you are dealing w/a normal distribution? well, let's see ... e