Find Minimum Sample Size Required for Unknown population mean mu OCC Math 160 Stats Final Review 10

The formula is in red to calculate the minimum required sample size.

Whenever there is a range within a population mean, you want to assume it's a 2-tailed test. In that case, you check Z-alpha/2 and cross reference your confidence interval. Since they want 90% confidence, the CI = 90%, or 0.90. Then, the Z a/2 for that range is 1.645. You should be able to find that on a chart.

Next, the given standard deviation, 28, is your sigma value. Lower-case sig looks like a dude's head with his toupee flying off.

Lastly, they want within 3.7 pounds of population mean. That means E (error) is 3.7.

Yes, all those Greek and Roman letters flying around can be confusing. Just keep repping it out.

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