Question

question 13 ch 17 null and alternative hypotheses always refer to a: sampling distribution. sample statistic. population parameter. sample estimates.

Explanation:

Null and alternative hypotheses are statements about population parameters. They are used in hypothesis - testing to make inferences about the population based on sample data. For example, we might test a hypothesis about the population mean $\mu$ or population proportion $p$. They do not refer to sampling distributions (which are distributions of sample statistics), sample statistics (which are used to estimate population parameters), or sample estimates (which are also sample - based values).

Answer:

C. population parameter