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Sample Size: Population Proportion

Can you show how to do this in Excel if possible?


1. A scientist wants to estimate the proportion of plants with berries growing in a particular region. They want to be within 6% of the true proportion when using a confidence interval of 99%.

How many plants must be sampled if no preliminary estimate is available?
(Remember when calculating a sample size, we need to round UP to the next whole number, not the closest whole number, if needed.

2. If less than that many plants is sampled, which answer best descrbes what happens?

a. The error is more than the desired error of 6%
b.The error is less than the desired error of 6%
c. The level of confidence must be increased
d. The confidence interval must be widened
e. A preliminary estimate is absolutely necessary

Solution Summary

The solution provides step by step method for the calculation of sample size. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.