Hi,
can someone help me solve this please I have tried so hard but can't figure it out? In past years, approximately 20% of all U.S. families purchased potato chips at least once a month. You are interested in determining the fraction of all U.S. families that currently purchase potato chips at least once a month. How many families must you survey if you want to be 99% sure that your estimate of the relevant proportion is accurate within 2%?
Thanks,
Ami

This sounds like one of the basic sample size questions you cover in Statistics. You can pop that into a web site like https://www.surveysystem.com/sscalce.htm to see how many samples for 99% confidence or interval.

commented: Hey thanks for the reply but is there a way i cam do it with excel? +0

Do it with Excel? Time for you to open up your old statistics book (or the web) and put in the formulas for what you want.

Also, you need to be able to do this on paper before you do such in Excel. If you can't on paper, you won't be doing this in Excel.

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