Example 4

The scores of a particular college admission test are normally distributed, with a mean score of 30 and a standard deviation of 2. Erin scored a 34 on her test. If possible, determine the percent of test takers whom Erin outperformed on the test.
  1. Sketch a normal curve and shade the area of the interval of interest.
  2. Determine how many standard deviations away from the mean Erin’s score is.
  3. Use symmetry and the 68–95–99.7 rule to determine the area of interest.
  4. Interpret the proportion in terms of the context of the problem.
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