A repeated samples from a population (M&M’s sampled from a bowl of them) give sl

Question

A repeated samples from a population (M&M’s sampled from a bowl of them) give slightly different estimates. This is used to introduce the concept of confidence intervals and the idea that statistical formula can be used in place of repeated sampling.1)the student sampled 50 M&M’s at a time. What effect would it have had if she had only sampled 20? What about 100 or 200?2) In real studies, do the data ever get eaten? 3)What would have happened if, instead of counting the number of brown M&M’s, the student had weighed them? 4)Why did Van Halen insist on having no brown M&Ms?

Explanation / Answer

We know that the confidence interval is given as

Mean +- Z*SD/Sqrt(N) , where

Z is the Z score from the Z table for the Confidence interval we are interested in , say 95% , 98% etc

SD is standard deviation

N is the sample size

also the standard error is Z*SD/Sqrt(N) , so if the value of N increases the standard error decreases , hence the width of the confidence interval decreases and we become more confident in our results

so increasing the sampling from 20 to 100 to 200 would only reduce the width of the confidence interval

Increasing the sample size decreases the width of confidence intervals, because it decreases the standard error.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.