00:01
In this problem, we are going to use slope and the slope formula to determine the rate of change in a human running a mile.
00:14
In the year 1906, we know that the record for a one mile run was four minutes and 30 seconds.
00:22
And then in 1957, the record was four minutes.
00:26
We are going to change those into ordered pairs.
00:29
We're going to let x be the year and y be the time it takes to.
00:35
Run a mile.
00:38
So x would be 1906 here.
00:41
And instead of four minutes, 30 seconds, 30 seconds is half of a minute.
00:46
So we're going to write that as 4 .5.
00:50
And then in 1957, it was four minutes.
00:57
So those are our two ordered pairs.
01:00
We can now use our slope formula, which is m equals y2 minus y1 over x2 minus x1, filling in with our ordered pairs.
01:16
The second y minus the first one would be 4 minus 4 .5 over our second x minus the first one, 1957 minus 1906.
01:39
Okay, cleaning that up, 4 minus 4 .5 is negative 0 .5 and 1957 minus 1906 is 51...