When to Use This Version

We would use this version of hypothesis testing when we do not know the population standard deviation $\sigma$ .

In this case, we have to rely on the sample standard deviation $s$ to estimate the population standard deviation $\sigma$ .

Assumptions The following assumptions are made:

1) The sample is obtained using simple random sampling

2) At least one of the following statements is true:

• The data are normally distributed
• The sample size $n$ is $30$ or more (the central limit theorem applies)