The data in the table shows that the percentage of adults in a country who are currently married is declining. Assuming that the percentage of adults who are married will continue to decrease according to the exponential decay model:

Year Percent of Adults Who Are Married
1960 73.6
1980 67.7
2000 57.3
2010 51.7
2012 48.6

a) Use the data for 1960 and 2012 to find the value of k.