1. Statistics Unit Check your understanding…

2. Can you answer these? What does the standard deviation of a sample represent? What is the difference between calculating the standard deviation of a sample or of a population? If you enter a sample into the stats list of your calculator and do a 1 variable stats on it, what does the σ x mean?

3. …and these? What does a z value mean? When you “look-up” a z-values on your z- score chart, what does this number mean? What must you know about your data before finding a z-score? What two things must be true before the results of a confidence interval calculation can be considered reliable?