Review K16 Paul and Carl have a chance at winning 46 + 3 means as low as 43% and high as 49% 43 + 3 means as low as 40% and high as 46% Paul and Carl have a chance at winning

Histograms We are learning to…create and analyze histograms and identify misleading graphs.

Histograms vs. Bar Graphs Many people confuse histograms with a bar graph. A histogram looks very similar to a bar graph. There are two big differences between a histogram and a bar graph. A bar graph compares items in categories while a histogram displays one category broken down into intervals. For example: A bar graph would compare…the number of apples, to the number of oranges, to the number of bananas at a grocery store. A histogram would compare…the number of people who eat 0-4 apples a week, to the number that eat 5-9, to the number who eat 10-14.

Histograms vs. Bar Graphs The bars on a histogram touch. The bars found on a bar graph do not touch. Why do you think that the bars will touch on a histogram? It will make intervals of data easier to compare.

Frequency Chart A Frequency Chart is a table that breaks data down into equal intervals and then counts the amount data in each interval. A Frequency Chart is often used to sort a list of data to make a Histogram. Make a Frequency Chart to display the data below: 90, 85, 78, 55, 64, 94, 68, 83, 84, 71, 74, 75, 99, 52, 98, 84, 73, 96, 81, 58, 97, 75, 80, 78 Interval 50-59 60-69 70-79 80-89 90-99 Frequency of Data 3 2 7 6 6

Don’t forget little things…like labels and equal intervals! Creating a Histogram Don’t forget little things…like labels and equal intervals! Interval 50-59 60-69 70-79 80-89 90-99 Frequency of Data 3 2 7 6 10 Math Test Scores 8 6 Frequency 4 2 50-59 60-69 70-79 80-89 90-99 100-109 Test Scores

Misleading Histograms What does it the word “misleading” mean? Deceptive or intentionally create a false impression. Misleading Histograms.xls Types of Misleading Histograms Combing Intervals: The amount of data in each interval can make a histograms look different. Stretched Graphs: Graphs might be stretched vertically so that data looks larger. Excluded Intervals: Intervals may be skipped on the x or y-axis to make the data look smaller.