Typically, you do the calculation for the standard deviation on your calculator or computer. The intermediate results are not rounded. This is done for accuracy.
- For the following problems, recall that value = mean + (#ofSTDEVs)(standard deviation). Verify the mean and standard deviation or a calculator or computer.
- For a sample: x = + (#ofSTDEVs)(s)
- For a population: x = μ + (#ofSTDEVs)(σ)
- For this example, use x = + (#ofSTDEVs)(s) because the data is from a sample
- Verify the mean and standard deviation on your calculator or computer.
- Find the value that is one standard deviation above the mean. Find ( + 1s).
- Find the value that is two standard deviations below the mean. Find ( – 2s).
- Find the values that are 1.5 standard deviations from (below and above) the mean.
OpenStax Introductory Statistics 2e, 2.7 Measures of the Spread of the Data, exercise 1