Statistics

Mean: average
Median: Middle number or average of the middle numbers when a list is in numerical order.
Mode: most often or most frequent
Range: Difference between the highest value and the lowest value.
Frequency table: table of intervals and their frequencies
Frequency Histogram: a bar graph representing values found from frequency table
Cumulative Frequency table: table of cumulative intervals' frequencies starting at the lowest interval
Cumulative Frequency Histogram: a bar graph representing the values found from the Cumulative table.
Quartiles and Percentiles

Lower quartile or 25th percentile: 25% of the score fall below a certain score.
Middle quartile or 50th percentile: 50% of the scores at or fall below a certain score.
Upper quartile or 75th percentile: 75% of the scores at or fall below a certain score.
Finding the nth percentile: set up a percentile proportion to find the one score the numbers in that percentile fall below, then count up from the lowest interval to find the number's interval.

Modal Interval: Find the interval that has the highest frequency
Median Interval: Find the nth middle number or numbers and count up starting at the lowest interval and find that number's interval.