#### Test statistic

A test statistic is the point estimate
of the parameter of interest, obtained from a sample. It is also called the
sample statistic.

For instance, if the analyst is interested
in the mean of a certain population the sample statistic is the sample mean,
which is referred as the test statistic. In order to perform a test of hypothesis
this test statistic is standardized. Therefore, the standardized test statistic
for the mean of the population becomes:

Standardized test statistic = (Sample
mean - Value from Ho)/ Standard deviation of sample mean