2.7 Exercise 1

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.

1. For the following problems, recall that value = mean + (#ofSTDEVs)(standard deviation). Verify the mean and standard deviation on a calculator or computer. Note that these formulas are derived by algebraically manipulating the z-score formulas, given either parameters or statistics.
2. For a sample: x = $\bar{x}$ + (#ofSTDEVs)(s)
3. For a population: x = μ + (#ofSTDEVs)(σ)
4. For this example, use x = $\bar{x}$ + (#ofSTDEVs)(s) because the data is from a sample

1. Verify the mean and standard deviation on your calculator or computer.
2. Find the value that is one standard deviation above the mean. Find ($\bar{x}$ + 1s).
3. Find the value that is two standard deviations below the mean. Find ($\bar{x}$ – 2s).
4. Find the values that are 1.5 standard deviations from (below and above) the mean.