For a random sample of size (n) taken from a random variable (X∼N(\mu, \sigma2)), the sample mean ((\bar{X})) is normally distributed with (\bar{X}∼N\bigg(\mu, \dfrac{\sigma^2}{n}\bigg)).
To perform the test:
- Define the test statistic
- Determine whether a one-tailed or two-tailed test is needed
- Identify the null and alternate hypotheses accordingly
- Calculate (P(\bar{X} < \bar{x})) and/or (P(\bar{X} > \bar{x}))
- Compare with the significance level of the test (usually (5%)) and decide whether or not to reject the null hypothesis
- Conclude with a statement in context of the question
[b]uSample mean of a Normally distributed random variable[/u]/b
(\bar{X}∼N\bigg(\mu, \dfrac{\sigma2}{n}\bigg))