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7.6 Practical Importance versus Statisti... > 7.6 Practical Importance versus Stat... - Pg. 202

202 Chapter 7 Suppose the sample data look like this: Sample size Sample mean Sample standard deviation 10,000 35.05 1.00 The t value is 5.0: t = X - p ffiffiffi s/ n 35:05 - 35 = p ffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1/ 10,000 = 5:0 The two-sided P value is 0.0000006. Because of the small sample standard deviation and the large sample size, the sample mean of 35.05 is five standard deviations from 35. The evidence is overwhelming that the population mean is not exactly equal to 35, but the practical difference between 35 and 35.05 is inconsequential. Now suppose the sample data look like this: Sample size 9