Question

We are interested in determining whether husbands differ from their wives on weight loss after taking a weight loss supplement. To evaluate this, we need to conduct a(n):

A. Independent samples t-test (*this was incorrect*)
B. Dependent samples t-test
C. One sample t-test
D. Any of these would be appropriate

My next best guess would be a one sample t-test but I am not sure anymore

Answer 1

As mentioned by you in the question that independent sample t-test is incorrect and your next guess is one sample t-test but even one sample t-test is not correct because in one sample a claim is made for the population and then that claim is tested using the samples.

For eg: we wish to check whether the population mean is 8 units, then we can take a sample of say size n and use the t-test to claim whether or not the population mean is 8 units based on that sample is size n.

Here the claim is made for 2 groups whether male and females differ in the weight loss after taking the supplements, so one sample t-test is not appropriate.

The answer to this is dependent sample t-test because initally we can note down the weight of all males and females before supplement and then take down the weights after supplement and then check whether the difference is same for both males and females using the dependent samples t-test, because the weights after supplements is dependent on the weight before the supplement hence dependent sample t-test is appropriate.