Hypothesis testing evaluates the likelihood that results from a particular sample reflect those of the population from which it is drawn.
The null hypothesis is the entire universe of possibility that excludes the study hypothesis.
The distribution of sampling means is the distribution of mean values from an infinite number of samples of a specific size.
- 4.The distribution of sampling means has three important properties:
Normal distribution for large sample sizes
Mean equal to the population mean
Variation inversely related to sample size and directly related to population variation
The p-value for comparing the means of two samples is calculated using the mean and standard deviation of each sample.
The p-value is the probability of obtaining the sample result, or more extreme result, if the null hypothesis were true. A low p-value (< 0.05) therefore implies that the null hypothesis is probably false and that the study hypothesis about the population is probably true.