Welcome to Excel 2013 video number four.
Hey if you want to download this workbook, Busn214-Week02.xlsx, click on the link below the video.
We have a short video here, I just want to make sure that we all know how to do a percentage increase or decrease formula.
So here we have our Revenue for January and each subsequent month it will increase by 1.5 percent.
So one way to create a formula is to have our formula input, not as 1.5 percent,
but as the number 1.015, that means when we multiply this times January, the one times the 20,000 gives us 20,000,
the .015 will give us the incremental increase of 1.5 percent, or as a decimal, .015.
So, equals, relative cell reference, times our rate,
F4 to lock it.
CTRL+Enter
Now, the cool thing about this is, as we copy it to the side, each one of these cells is looking at the month before, increasing by 1.5 percent.
Now here we're going to do an increase and decrese problem, the formula for them is the same, it's the same as up here,
but oftentimes we're not given what's called a rate, in the business math class I teach they always call this the rate,
this is the percentage or number you multiply by the begin amount, to get to the end.
So here's our start, we could have our investment increase by ten percent
or we could have it decrease by ten percent or whatever percentage change it is.
The formula to go from the start to the end is always going to be the same.
Now one way to look at this, and if you look at Excel formulas, alot of times you'll see this,
you'll see whatever the start amount is, plus the start amount, times whatever the percentage change is.
And this percentage change could be minus or positive.
However, there's a slightly more efficient formula and it comes, or it is derived from the fact that
this math expression can be converted using factoring.
Now think about this, this is one thousand times one, plus one thousand, times whatever the percentage change or decimal change is.
So notice anytime you have a plus symbol and the same number times some other number,
same number times one, plus same number times the percentage change, you can factor out the same number.
So you can factor out the 1,000.
So what we're left with is, you factor out the thousand, and it's on the outside,
times, and then you leave the two other numbers that were multiplied by that, inside the parenthesis with the plus symbol.
We factored out the 1,000, a one was left here, a .10 was left here.
So, 1,000 times 1 plus the percentage change, that's the formula we're going to do here when we're doing percentage change.
The fact that we can go 1,000 times 1.1, sometimes you get a rate given to you like that, that would be more like this formula here.
So, you ready?
Equals, the "Start", times one, plus the "% Change".
Alright?
And if you do the distributive property, which is the reverse of factoring,
you take the 1,000, times the one, and then the 1,000 times the percentage change, and then add them together.
So, 1,100, if I use the CTRL+Shift+4, that's the keyboard to give me Currency,
I can see that that formula works in either case.
So, the formula that we're going to use oftentimes is "Start", times one, plus the "% Change",
and it could be plus or minus, equals the End.
And that would be our formula.
Now, I want you to notice I was sorta loose with my language here, sometimes I said percentage change, sometimes I said the actual decimal.
Hey, as we saw last video, even if you have % Change, it always, underneath, calculates to a decimal.
Ten percent change or point one zero, in essence they are synonyms for the same number, point zero one.
Alright, we'll see you next video.