PSYCH 100A Chapter Notes - Chapter 3: Frequency Distribution, Histogram, Unimodality
Document Summary
Tabular frequency distribution: table that lists the numerical values of a variable in a logical order along with frequency of each value. Convention: largest value of the variable placed first. Frequency: number of times a particular value of the variable occurs. Grouped frequency distribution: adjacent values of the variable are grouped together. Frequencies are reported for the intervals not for the individual weights. Each interval must be the same width, non-overlapping and consecutive. Make a preliminary choice of the desired number of intervals. Determine the interval width by dividing the range of by the number of intervals. Prepare a list of limits of each class interval beginning at the bottom of the table with the lowest score and proceeding upwards. Count the number of observations that occur in each interval. Histogram: plot of class intervals on the horizontal axis and the frequency on the vertical axis. Intervals are represented by bars with the height of the frequency.
