00:01
All right, so this next one deals with the consumer price index or the cpi, which basically helps me know the purchasing power of my money.
00:12
So the base cpi is 100, and it's normally in 1982.
00:18
That's as if i could buy so many goods with $100 in 1982, but let's say my cpi in 2014 is 236.
00:28
To buy those same goods, it would cost me $236 in 2014.
00:36
So this question wants me to find on a different scale than initial cpi.
00:44
It says that in 1995, my cpi was 456 .5, and my annual inflation rate was 5 .57%.
00:58
And i want to find what year that that base cpi is.
01:06
So i know my ending cpi of 456 .5.
01:13
And i know my original.
01:16
So if i'm looking for my initial, the base pair is always going to be 100.
01:24
My rate is at just 5 .57.
01:31
And this formula has r as a percent so i don't have to move through decimal places.
01:37
And i'm trying to find what year it was.
01:40
So i'm going to need to find n first.
01:44
So first thing i'm going to do is divide each side by 100.
01:50
Because i want to get this n by itself.
01:54
And to do that, i'm going to have to take a natural log later on...