Dependent Variable
With single samples and one dependent variable, the one-sample Z test, the one-sample t test, and the chi-square goodness-of-fit test are the only statistics that can be used. Students sometimes ask, "but don't you have population data too, so you have two sets of data?" Yes and no. Data have to exist or else the population parameters are defined. But, the researcher does not collect these data, they already exist. So, if you are collecting data on one sample and comparing those data to information that has already been gathered and is published, then you are conducting a one-sample test using the one sample/set of data collected in this study. For the chi-square goodness-of-fit test, you can also compare the sample against chance probabilities.