To investigate the maternal behavior of laboratory rats, we move the rat pup a fixed distance from the mother and record the time (in seconds) required for the mother to retrieve the pup to the nest. We run the study with 5- and 20 day old pups. Note: These are not the same pups being measured twice.
5 Days | 20 Days
15 | 30
10 | 15
25 | 20
15 | 25
20 | 23
18 | 20
Create an appropriate 95% confidence interval to test if the average retrieval time differs per group. To receive full credit, state the null/alternative pair, statistical decision based on the confidence interval and interpretation. Assume both populations come from approximate normal distributions.