Mini Lesson 3: Show and describe variability Make a Histogram Data Literacy Project

How do the heights of 17 boys and girls vary? Dot Plot Histogram How is a dot plot and histogram similar? How are they different?

How do the heights of 17 boys and girls vary? Histogram How is a histogram and bar graph similar? How are they different? Bar Graph

Histogram A histogram is a bar graph that displays frequency rather than compares groups. Usually the data is grouped in equal- sized intervals (bins) that do not overlap but the bars will often touch. The height of each bar shows the frequency of the data in a given interval or bin.

Making a histogram: 1. Decide on an interval or bin size Example: 16 batteries are tested and the hours that each lasts is recorded Data (hours): 9, 12, 14, 10, 15, 10, 18, 23, 10, 14, 22, 11, 9, 10, 11, 12 Lowest number : 9 hours Highest number : 23 hours Range: 23 – 9 = 14 Bin or intervals could be 2, 3, 4, 5 I will choose a bin size of 3

Making a histogram: 2.Make a frequency table and tally data into each bin or interval Data (hours): 9, 12, 14, 10, 15, 10, 18, 23, 10, 14, 22, 11, 9, 10, 11, 12 IntervalTallyFrequency l l l l l l l l l 2

Making a histogram: 3. Plot data as connecting bars

Comparing Histogram to Dot Plot