The scatter diagram drawn in MINITAB shows the relation between the percentage of the population of a

state plus Washington, DC, that has at least a bachelor€™s degree and the median income (in dollars) of the state for 2009.
(a) Describe any relation that exists between level of education and median income.
(b) One observation appears to stick out from the rest. Which one? This particular observation is for Washington, DC. Can you think of any reasons why Washington, DC, might have a high percentage of residents with a bachelor€™s degree, but a lower than expected median income?
(c) The correlation coefficient between the percentage of the population with a bachelor€™s degree and median income with Washington, DC, included in the data set is 0.718. The
correlation coefficient without Washington, DC, included is 0.802. What property does this illustrate about the linear correlation coefficient?

Transcribed Image Text:

Percent of Population with a Bachelors versus Median Income 65000 60000 55000 c 50000 45000 40000 35000 20 25 30 Percent Bachelors 35 40 45 50