A Statistician Measures the Difference in Songbird Warble Variation in 25

A statistician measures the difference in songbird warble variation in 25 mockingbirds, both before and after nutritional supplementation with Dr. Petit Oiseau's Musical Bird Seed. Warble variation is determined by a computer program that detects sound frequency and pattern changes during a 15-minute period twice a day, and these data are averaged to represent number of warble variations per minute. What considerations determine choice of a test for this research?

A) The sample size is small to moderate.
B) There is one group of birds and all receive the treatment.
C) A before-after type of design is used.
D) The independent variable is at the nominal level.
E) Birds are divided into two groups.
F) The independent variable is ratio level.
G) The dependent variable is ratio level.