Though the northernmost islands experience a bit of rain, September is largely dry, warm and sunny throughout the islands. High season in Hawaii doesn't start till mid-December, so September is still off-season for the Hawaii tourism industry and deals abound.
T-tests and analysis of variance (ANOVA) are widely used statistical methods to compare group means. For example, the independent sample t-test enables you to compare annual personal income between rural and urban areas and examine the difference in the grade point average (GPA) between male and female students.
One of the assumptions of an anova and other tests for measurement variables is that the data fit the normal probability distribution. Because these tests assume that the data can be described by two parameters, the mean and standard deviation, they are called parametric tests.