| A | B |
|---|
| central tendency | a statistical measure to determine a single score that defines the center of a dsitribution. |
| goal of central tendency | to find the single score that is most typical or most representative of the entire group |
| the mean | a sum of all the scores divided by the number of scores |
| symbol for the mean of a population | µ |
| symbol for mean of a sample | M or x-bar |
| Formula for the population mean | μ = ΣX/N |
| formula for the sample mean | M= ΣX/n |
| the entire population | N |
| the sample population | n |
| median | the score that divides the distribution in half so that 50% of the individuals are above & 50% are below |
| mode | the score or category that has the highest frequency |
| symmetrical distribution | the right hand side of the graph is a mirror image of the left-hand side (Mean=Median=Mode) |
| bimodal | a continuous distribution with two different modes. |
| multimodal | a continuous distribution with more than one node |
| major mode | in a multimodal distribution the tallest peak |
| minor mode | in a multimodal distribution, peaks other than the highest peak |
| skewed distribution | asymmetric distribution either to left or right |
| positive skew | a distribution is skewed to the right (Mean>Median>Mode) |
| negative skew | a distribution is skewed to the left (Mean<Median<Mode) |
| weighted mean | The weighted mean is similar to an arithmetic mean (the most common type of average), where instead of each of the data points contributing equally to the final average, some data points contribute more than others |
