00:01
So in this question, they say that the average life expectancy after age 65 is sore, putting pressure on the social security administration's resources.
00:14
According to the social security trustees, the average life expectancy after age 65 is given by l of t, which is equal to .056 t plus 18 .1 for t values for from 0 to 7, where t is measured in years, with t equals 0, corresponding to 2003.
00:40
In part a, they say, how fast is the average life expectancy after age 65 changing at any time during the period under consideration? well, this is just the slope.
00:57
Okay, this is just the slope of this line.
01:03
So it's 0 .056.
01:06
So it is increasing at 0 .056 years each year.
01:20
In other words, every year that passes life expectancy is increasing at the rate of 0 .056 years per year.
01:32
And then in part b, what will be the average life expectancy after age 65 in 2010? well, remember, t equals zero corresponded to 2003...