40
The sample size required to estimate a population mean with a certain level of confidence and a desired margin of error is calculated as:
Sample size =(zα/2σ/E)2
where:
- zα/2: The z critical value
- E: The desired margin of error
- σ: The population standard deviation
To find the sample size required to estimate a population mean, simply fill in the boxes below and then click the “Calculate” button.
Sample Size: 35