Example 2

In order to constantly improve instruction, Mr. Hoople keeps careful records on how his students perform on exams. The histogram below displays the grades of 40 students on a recent United States history test. The table next to it summarizes some of the characteristics of the data. Use the properties of a normal distribution to determine if a normal distribution is an appropriate model for the grades on this test.
  1. Analyze the histogram for symmetry and concentration of values.
  2. Examine the distribution for outliers and evaluate their significance, if any outliers exist.
  3. Determine whether a normal distribution is an appropriate model for this data.
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