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Example of the Sign Test



In 1995, the median salary of U.S. doctors was $140,900. A random sample of 15 physicians showed 1999 incomes of:

 145,000

 150,300

 122,600

 218,000

 252,500

 126,800

 131,700

 151,400

 134,500

 142,000

 120,000

 138,000

 128,600

 145,500

 157,200

Does it appear that the median salary of U.S. doctors was greater in 1999 than it was in 1995?

Sign Test for Median: Salary

Sign test of median = 140900 versus  >  140900

               N  Below  Equal  Above         P     Median
Salary        15      7      0      8    0.5000     142000





Gary Sneddon 2003-11-07