Histograms

What is a Histogram? A histogram is a vertical bar graph that shows the frequency of related events A histogram doesn’t have space between the bars on the graph A histogram has intervals on the X axis and (usually) explains frequency on the Y axis

Histograms – Key Points Require a title Require a label on the X and Y axis Require Units (if possible) on the X and Y axis Require that the values on your X and Y axis make sense *NO SPACE BETWEEN BARS!!*

To make a Histogram... First, make a Frequency Distribution Table (3 columns...data, tally, frequency—from last week) Group your results into intervals (usually intervals of 5 or 10)

Example In this example, the Frequency Distribution Table has been made for you. Watch the board to see how to make your histogram. Pay attention to what info you place where! ScoresTally Frequency 41-50I II IIII I III II2

Question A Here, the Frequency Distribution Table has been done for you. Create the Histogram for this data ScoreTally Frequency 0-15III IIII IIII IIII III8

Question B Bob threw 25 darts at the same dartboard. Here are his scores: 0, 36, 24, 50, 10, 0, 12, 45, 24, 20, 10, 0, 32, 0, 14, 40, 16, 30, 24, 38, 16, 0, 30, 22, 26 Create a histogram for this data. (Remember you must first place your data into a Frequency Distribution Table!)

Question C The Toronto Raptors need your help. They need to organize the number of points they have scored in each of 30 games into some sort of graph. Look at the data below and create a histogram for them. (Be sure to make your graph neat – you will be coloring it in and putting it up on the back wall...) 101, 112, 64, 48, 100, 99, 123, 88, 98, 54, 67, 103, 109, 100, 87, 65, 78, 75, 69, 73, 77, 86, 89, 93,94, 107, 100, 106, 121, 89

Question C 1.What is the mean number of points scored? 2.What is the mode for the point totals? 3.What is the median for the point totals? 4.What is the range of points scored? 5.Which value above – mean, median, mode or range – can be most easily found from the histogram?