Targeting interest rates using open market operations is the most important policy tool used by the Fed to conduct monetary policy. Consider the accompanying table which lists the federal funds rate and other key interest rates over the past decade.

Date	Federal Funds Rate (%)	Discount Rate (%)	Prime Rate (%)	30‑year Mortgage Rate (%)	Difference between discount rate and federal funds rate (%)	Difference between prime rate and federal funds rate (%)	Difference between 30‑year mortgage rate and federal funds rate (%)
12/1/2006	5.24	6.25	8.25	6.14	1.01	3.01	0.90
6/1/2007	5.25	6.25	8.25	6.66	1.00	3.00	1.41
12/1/2007	4.24	4.75	7.33	6.10	0.51	3.09	1.86
6/1/2008	2.00	2.25	5.00	6.32	0.25	3.00	4.32
12/1/2008	0.16	0.50	3.61	5.33	0.34	3.45	5.17
6/1/2009	0.21	0.50	3.25	5.42	0.29	3.04	5.21
12/1/2009	0.12	0.50	3.25	4.93	0.38	3.13	4.81
6/1/2010	0.18	0.75	3.25	4.74	0.57	3.07	4.56
12/1/2010	0.18	0.75	3.25	4.71	0.57	3.07	4.53
6/1/2011	0.09	0.75	3.25	4.51	0.66	3.16	4.42
12/1/2011	0.07	0.75	3.25	3.96	0.68	3.18	3.89
6/1/2012	0.16	0.75	3.25	3.68	0.59	3.09	3.52
12/1/2012	0.16	0.75	3.25	3.35	0.59	3.09	3.19
6/1/2013	0.09	0.75	3.25	4.07	0.66	3.16	3.98
12/1/2013	0.09	0.75	3.25	4.46	0.66	3.16	4.37
6/1/2014	0.10	0.75	3.25	4.16	0.65	3.15	4.06
12/1/2014	0.12	0.75	3.25	3.86	0.63	3.13	3.74
6/1/2015	0.13	0.75	3.25	3.98	0.62	3.12	3.85
12/1/2015	0.24	1.00	3.37	3.96	0.76	3.13	3.72
6/1/2016	0.38	1.00	3.50	3.57	0.62	3.12	3.19
12/1/2016	0.54	1.25	3.64	4.20	0.71	3.10	3.66
6/1/2017	1.04	1.50	4.13	3.90	0.46	3.09	2.86
12/1/2017	1.3	1.75	4.4	3.95	0.45	3.10	2.65
6/1/2018	1.82	2.25	4.89	4.57	0.43	3.07	2.75
12/1/2018	2.27	2.75	5.35	4.64	0.48	3.08	2.37

Consider the three columns in the table which list the difference between the federal funds rate and each key interest rate for all of the given periods. Identify the maximum and minimum differences between the federal funds rate and each of the key interest rates.

What were the maximum and minimum differences between the discount rate and the federal funds rate?

Maximum:______%.

Minimum:______%.

What were the maximum and minimum differences between the prime rate and the federal funds rate?

Maximum:______%.

Minimum:_____%

What were the maximum and minimum differences between the 30‑year mortgage rate and the federal funds rate?

Maximum:______%.

Minimum:_______%.

Based on these value, the_________ is least likely to change in direct proportion to the federal funds rate.

Choices: 

Discount rate, prime rate, or 30-year mortgage rate