| A | B |
|---|
| Lower class limits | the lower value of a class in a frequency distribution that has the same decimal place value as the data |
| Upper class limits | the upper value of a class in a frequency distribution that has the same decimal place value as the data |
| Clas boundaries | the upper and lower values of a class for a gouped frequency distribution whose values have one additional decimal place more than the data and end in the digit 5 |
| Class width | the difference between the upper class boundary and the lower class boundary for a class in a frequency distribution |
| Three types of frequency distribution charts | categorical, grouped, and cummulative |
| Three most commonly used graphs in research | histogram, frequency polygon, and the cummulative frequency graph |
| Find the range of a set of data | Highest value minus the Lowest value (H-L) |
| Different distribution shapes of graphs | bell-shaped or mound-shaped, the unifrom shaped, the J-shaped, the reverse J-shaped, the right-skewed shape, the left-skewed shape, the bimodal shaped, and the U-shaped |
| Percentile | location measue of data value; it divides the distribution into 100 groups |
| Quartile | a location measure of a data value; it divides the distribution into four groups |
| Decile | a location measure of a data value; it divides the distribution into 10 groups |
| Empirical Rule | a rule that states that when a distribution is bell-shaped (normal), approximately 68% of the data values will fall within 1 standard deviation of the mean; approximately 95% of the data values will fall within 2 standard deviations of the mean; and approximately 99.7% of the data values will fall within 3 standard deviations of the mean. |
| Parameter | a characteristic or measure obtained by using all the data values for a specific population |
| Statistic | the science of conducting studies to collect, organize, summarize, analyze, and draw conclusions from data |
| Measures of central tendency | Measures of Average that includes Mean, Median, Mode, Midrange |
| Measure of variation | The measures that determine the spread of the data values; measures of dispersion |
| Measure of position | These measures tell where a specific data value falls within the data set or its relative position in comparison with other data values. They are referred to as norms. They are used in psychology and education. These measures include standard scores, percentiles, deciles, and quartiles. They are used to located the relative position of a data value in the data set. |
| Class midpoint | a value for a class in a frequency distribution obtained by adding the lower and upper class boundaries (or the lower and upper class limits) and dividing by 2 |
| Standard Deviation | Square root of the variance |
| Variance | Average of the squares of the distance that each value is from the mean |
