Test to see if the sample mean is significantly different from 65 at the .05 level. Ten subjects are each tested twice, once after having two drinks and once after having two glasses of water. The two tests were on two different days to give the alcohol a chance to wear off. Half of the subjects were given alcohol first and half were given water first. The scores of the 10 subjects are shown below.
Higher scores reflect better performance.
Test to see if alcohol had a significant effect. Use the .01 significance. The experimenter wants to know whether the correlation between tasks one and two is significantly different from the correlation between tasks two and three. Test the difference for significance using the .05 level. An experiment conducted by Michael Murphy-Corb and his associates tested a new vaccine against aids in monkeys.