Question

The t statistic compares two groups on one independent variable that has two levels. We can use the t statistic to compare a sample that has a level of an independent variable, or we can use two samples from the same populations and give them two different levels of an independent variable. You will design a two group study with one independent variable for this question. Choose an independent variable that has two levels. The two levels can be 1.) present in the group or 2.) absent in the other group or you can have two different amounts or types of the independent variable. Then choose the dependent variable(the way we will measure the effect of the independent variable) for both groups.

Answer 1

Since we want to measure the effect of the independent variable, so we choose dependent variable with absence of independent variable i.e. when we do not use independent variable, the we collect the observation of dependent variable. Similarly, we choose dependent variable with presence of independent variable i.e. when we use independent variable, the we collect the observation of dependent variable. Therefore we get two groups of observations. First set of observations belongs to the group where the independent variable is absent and second set of observations belongs to the group where the independent variable is present. Now we compare these two groups using 2 sample t test and check whether the independent variable significantly influence the dependent variable or not.