A Biopsychologist Is Interested in Studying the Effects of Marijuana

A biopsychologist is interested in studying the effects of marijuana on cognitive skills by studying a group of 7 rats.He puts each rat in a maze and measures the time it takes the rat (in minutes) to find the cheese at the end of the maze.He then puts a mask on the rat and has it inhale marijuana smoke for 5 seconds.He then puts the rat back in the maze,and records its time to reach the cheese.Twenty minutes later he puts the rat back in the maze to test for lasting effects of the drug.The tables below summarize the data and part of the data analysis:

In your ANOVA summary table,the ______ source reflects variability in maze completion time (the dependent variable.that is due to disturbance variables such as individual differences;the purpose of partitioning this source of variability is to ______.

A) IV;test your null hypothesis
B) Error;use it as the denominator in the F ratio
C) Across Subjects;use it as the denominator in the F ratio
D) Across Subjects;separate it from other sources of error