Testing a Single Mean
Completion requirements
This section shows how to test the null hypothesis that the population mean is equal to some hypothesized value, using a very concrete example. In this example, all the main elements of hypothesis testing come in to play a role.
Testing a Single Mean
Answers
- The population standard deviation is known.
- The standard error of the mean is \(2.5\). You then find the probability of a sample mean more than \(25-20=5\) from the population mean of \(20\). This is the probability outside \(15\) and \(25\) given a distribution with a mean of \(20\) and a standard deviation of \(2.5\). The probability is .0455.
- \(2.6693\) Make sure you divide by \(\mathrm{N}-1\).
- \(0.9437\) You divide \(s\) by the square root of \(\mathrm{N}\).
- You divide \(\mathrm{M}=1.625\) by the standard error of the mean \((.9437)\) to get \(1.72\).
- You use \(N-1=7\) degrees of freedom. \(p=.1288\)
- \(t=1.4626\)
- \(t=-0.7917\)
- \(p=0.8319\)