A scientist who works in animal physiology wants to study perception of UV light in rats. She randomly selects 20 rats and records how far each rat travels in 5 minutes inside a dark maze. The distance is recorded and then the rats are returned to the starting position. The maze is then "illuminated" with UV light and the rats are again given 5 minutes to travel through the maze. This distance is then recorded. Which hypothesis test would be most appropriate for this study?

(a) One sample z-test, why?
(b) One sample t-test, why?
(c) Paired-samples t-test, why?

c)

Step-by-step explanation:

Hello!

The researcher took a random sample of 20 rats.

First left each of them inside a dark maze for 5 minutes and recorded how far each rat got.

Then, using the same random sample, she "illuminated" the maze with UV light and repeated the experiment, recording how far the rats got after 5 min.

At the end of the experiment, the researcher has two distances recorder for each rat, one in the darkness and one illuminated with UV light. Since both variables "distance traveled in the dark maze" and "distance traveled in the maze illuminated with UV light" were measured using the same experimental units they are dependent.

Z-test is more accurate when sample sizes tend to infinite (for example larger than 100) and t-tests are more accurate for small samples. The sample is n=20 so the best statistic is the t-test.

The test to apply is a Paired-samples t-test.

I hope it helps!

30 people weigh 160 pounds or more