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  • Quantitative Data

Histogram

• A Histogram is a way to represent Quantitative Data.

• Like a bar chart but only for Quantitative Data.

• Class intervals are our bins and we have frequency per bin.

• We can collect data in a Frequency Table

• Advantages:

  • Easy to interpret.
  • Can give us what the distribution might be.

• Disadvantages:

  • Not good for small data
  • Can be sensitive to bin width

• What should our bin size be

• Estimating the mean using a histogram

• (2. Descriptive Statistics, p.28)

• Ex:

  • $$\begin{array}{ccccc}\text{Class Interval}& \text{Freq}& \text{Relative Freq}& \text{Cumulative Freq}& \text{Cumulative Relative Freq}\\ [20,40)& 4& 0.133& 4& 0.133\\ [40,60)& 12& 0.4& 16& 0.533\\ [60,80)& 9& 0.3& 25& 0.833\\ [80,100)& 3& 0.1& 28& 0.933\\ [100,120)& 2& 0.067& 30& 1\\ & 30& 1\end{array}$$
  • Graphic: (2. Descriptive Statistics, p.33)
  • This looks like a Gamma Distribution