- #1

Richard_R

- 14

- 0

I am having to brush up on my stats for work and it's been a long time (>10yrs) since I've had to even think about this stuff. I could do with some help clarifying a specific point about standard errors and margin of error.

An example I am looking at from my old notes is this: the manager of an ice-cream shop wants to know the average amount of ice-cream his staff put into each ice-cream cone. If 50 samples are taken with an average (mean) of 10.3 ounces and a standard deviation of 0.6 ounces then what is the margin of error (MOE) at the 95% confidence level?

Now I think I've worked out the answer correctly:

MOE @ 95% CL = 1.96 x 0.6/SQRT50 = 0.17 ounces

I.e. MOE = 10.3 oz +/- 0.17 oz at 95% CL

However I am not totally sure how to interpet this result. Does this mean that if I redid the experiment again and again that 95% of the

*individual*results in each sample would be within that range (10.3 +/- 0.17) or that the

*mean*from each sample would be within that range, or both?

I think it's the sample means as standard errors and margins of error have to do with sample means (or proportions) but am not 100% sure...

Thanks!

-Rob