In the following studies, state whether you would use a one-sample t test or a two-independent-sample t test.
A. A study testing whether night-shift workers sleep the recommended 8 hours per day.
B. A study measuring differences in attitudes about morality among Democrats and Republicans.
C. An experiment measuring differences in brain activity among rats placed on either a continuous reward schedule (rewarded every time behavior is exhibited) or an intermittent reward schedule (rewarded after every few times behavior is exhibited).

Step-by-step explanation: The one - sample t-test is used to determine the existence of a statistical difference between a sample mean and a given population mean. The one sample t test is only capable of making comparison between a singular sample mean and an established value. Such is the case in (A) where the aim is to determine if a group of night workers sleep for 8 hours.

The other two cases however, involves making comparison between the sample means of two different groups, this requires the use of a two independent sample t-test

For a one-sample t test:

(Sample mean - population mean) / standard error.

Sample mean = s

Population mean = p

Sample size = n

For a two sample t-test :

[(s2 - s1) - (p2 - p1)] ÷ √[(sd1^2/n1) + (sd2^2/n2)]