Posted: February 11th, 2016

Estimating a Population Proportion-Formats of Confidence Intervals

Question:
Express the confidence interval using the indicated format. (The confidence intervals are based on the proportions of red, orange, yellow and blue M&M’s in Data Set 20 from Appendix B which is attached). Chapter information is also attached.

Express the confidence interval 0.165 < p < 0.335 in the form of p^ ± E.

Below is a step by step possible answer/solution to the question. Please work the same problem out doing it your own way (POST YOUR COMPLETE & DETAILED SOLUTION) and see if you come up with the same answer. If your answer differ, say why.

STEPS:

Point estimate of p

p^ = ((upper confidence interval limit) + (lower confidence interval limit)) divided by 2.

p^ = (0.335 + 0.165)/2

p^ = .5/2

p^ = .25

Margin of error

E = ((upper confidence interval limit) – (lower confidence interval limit)) divided by 2.