00:01
So we know that we're going to let time be after 2006.
00:05
So at time zero, we're starting out with the revenue being 49 .3, and that will be in billions of dollars.
00:13
And that's the revenue.
00:16
And in 2013, which is seven years later, we're at 20 .7.
00:22
So we want to find that k constant.
00:24
So if we start with 49 .3 billion, and e to the k times t, and t would be 7 and we want that money to end up being 20 .7.
00:37
So we divide by our base, our value here.
00:52
For some reason, i'll turn as a continuous.
00:55
So this is supposed to be a 0 .7 here.
01:01
And now we will take the natural log of both sides, that quantity, and we can do log of the power and the 7 times k comes down and ln of b is 1 and then we'll divide by our 7.
01:17
So when i type in and this is a 20 .7 and this is a 49 .3.
01:24
So natural log of 20 .7 divided by in parentheses 49 .3 and then divide that by 7...