You are studying the effect of depression on a university student's cognitive ability. Your supervisor claims that in the past 20 years the mean score on her cognitive ability test for people WITHOUT any signs of depression is 86.4 (st dev = 18.8, higher numbers are better). You hypothesize that people with depression will perform more poorly on your cognitive test because research has consistently shown that people with depression have more difficulty with cognitive tasks.You run a small study with just 12 people who have been diagnosed with depression to estimate your effect size.You find that these 12 people had a mean score of 81.8 (st dev = 17.4).If this represents an accurate estimate of the scores that people with depression score, how many people would you have to include in your research to obtain a power of .80?