A statistic is a number that describes some characteristic of a sample.
A parameter is a number that describes some characteristic of a population.
The table below shows three commonly used statistics and their corresponding parameters. These symbols are widely used in statistics and you are expected to know and use these symbols and terms. The symbol for sample mean is read "x bar" and the symbol for sample proportion is read "p hat." PLEASE get out your notebook and write down the following symbols and their meanings:
| Sample Statistic |
|
Population Parameter |
| \(\bar x\) (sample mean) |
estimates |
\(\mu\) (population mean) |
| \(\hat p\) (sample proportion) |
estimates |
\(p\) (population proportion) |
| sx (sample st. dev) |
estimates |
\(\sigma\) (population st. dev) |
Use the following scenario for the questions below:
From a large group of people who signed a card saying they intended to quit vaping, 1000 people were selected at random. It turned out that 210 (21%) of these individuals had not vaped over the past 6 months.
