This scatterplot to the left shows the relationship between

This scatterplot to the left shows the relationship between the percentage of the population of a state (Washington, DC included) that has at least a bachelor’s degree and the median income (in dollars) of the state for 2009. Each point on the graph represents a separate state. Source: U.S. Census Bureau

a.) Describe the correlation between the percentage of the population with at least a bachelor’s degree and the median income, being sure to specifically note the strength and direction of the correlation.

b.) One observation seems to stick out from the rest. Circle it on the scatterplot. This particular observation is for Washington, DC. Describe why Washington, DC might have a high percentage of residents with a bachelor’s degree, but a lower than expected median income?

Percent of Population with a Bachelors versus Median Income 65000 60000 55000 50000 45000 400001 . 35000 40 45 50 30 Percent Bachelors 20 25 35

Solution

Answer to the question is as follows. I have also mentioned detailed reasoning with the answers for your benefit. Please don\'t hesitate to give a \"thumbs up \" if you are satisfied with the answer.

a.

If you were to draw a best-fit line, it would be a trending positive line. The correlation is a strong correlation in strength as you can see clearly a trend. Also, the correlation is positive in direction. i.e. with higher percent bachelor\' we have higher median income

b. You can circle the observation with X = 47.5, Y = 55000 as below.

DC may have high percentage of bach\'degree but a lower than expected median income because DC has more government jobs, which pay lower than a private firm\'job. Hence, the median is also lower compared for DC compared to other cities.