A researcher determines that high school girls miss more days of school than high school boys. A sample of 16 girls showed that they missed average of 3.9 days of school per year; a sample of 22 boys showed that they missed average of 3.6 days of school per year. The standard deviations of two samples are 0.6 and 0.8 respectively. At ? = 0.01, is there enough evidence to support researcher's claim? A Probability plot and box plot showed that both variables are distributed normally as well as have no outliers.