For each of the following pairs of variables, pull the data from the St. Louis Federal Reserve FRED database and create a scatterplot graph of the two variables using Excel.

For each pair, name the exogenous variable relative to the endogenous variable, and indicate whether the variables are unrelated.

a) Personal Income (PINCOME) and Personal Consumption Expenditures (PCEC), quarterly data since 1980 Q1.

b) Total Nonfarm Payrolls (PAYEMS) and M1 money supply (M1SL), monthly data since January 2000.

c) Personal Saving Rate (PSAVERT) and the 10-year US Treasury Rate (GS10), monthly data since January 1980.