For this lesson you need to open the sample file 
UK House Prices-1 from your Sample Files 
folder.
This lesson introduces Trend Analysis.
If a value has been increasing for a long time, 
trend analysis would suggest that it will go on 
increasing. 
Some would say that the reverse is true, but 
Excel remains healthily optimistic that we can 
predict the future from the past.
Excel provides several different types of trend 
analysis. 
We're going to use a Linear Trendline and a Two 
Period Moving Average, to decide whether it was 
a good idea to buy a house in 2008. 
So let's begin by removing the Minimum Base 
Rate data series and corresponding Axis from 
the chart. 
You learned how to do this in Lesson 5-14.
To do this I'll right click in the center of the chart 
and then choose Select Data from the Shortcut 
Menu. 
And on the left hand side of the dialog you can 
see both data series.
I'll select the Min Base Rate data series and 
then click the Remove button. 
I'll then click OK.
And you can see that we now only have one 
data series, 
and that the Minimum Base Rate Data Series, 
along with its Vertical Axis, have now been 
removed from the chart. 
Now we're going to add a Linear Trendline 
element to forecast where property prices will be 
in the Year 2014. 
To do that you first need to activate the chart if 
it's not already activated, by clicking just inside 
the border. 
You know that the easiest way to add an 
element is by clicking the Chart Elements 
button at the top right of the chart. 
And you can see the Trendline element towards 
the bottom of the list. 
When I hover the mouse over the Trendline 
element, you can see there's a fly-out menu.
So I'll click the fly-out menu arrow and then I'll 
click More Options to give me complete control 
over the Trendline I'm going to add. 
The Format Trendline Task Pane now appears.
I want a Linear Trendline so I’ll leave the 
selection at Linear. 
And you can see that the Linear Trendline is 
already being shown on the chart. 
Let's now scroll down to some of the options 
and you can see that I can add a Forecast 
option. 
And I wanted to forecast where house prices 
would be in 2014.
Now because the Axis is moving in single years, 
and because 2014 is six years after 2008, I'm 
going to enter 6 in the Forward Forecast box.
I'll now press the Enter key, and you can see on 
the chart that we can already see the Forecast 
Trendline. 
And I'll now close the Format Trendline Task 
Pane.
You can see that the chart's unable to display 
the years at the moment, as it's not wide 
enough. 
So I'll also re-size the chart so that the years 
show clearly. 
And you can see that Excel believes that in 
2014 the house that you bought for 186,958 in 
2008 
would be worth well over a quarter of a million.
In this particular example, Excel didn't forecast 
very well. 
But let's look at a different type of trendline that 
might give us a better forecast. 
First of all, I'll click on the Trendline to select it, 
and then I’ll press the Delete key on the 
keyboard to remove the Linear Trendline.
Now I'm going to add a different type of indicator: 
A Two Period Moving Average. 
Moving averages are one of the most loved 
instruments of speculators 
who predict future values of shares, currencies 
and commodities, based entirely upon charts.
The theory is that when the price crosses 
beneath the moving average, it's time to sell.
Once again, we need to add a Trendline 
element. 
So I'll click the Chart Elements button and then 
hover the mouse cursor over the Trendline 
element. 
And then I'll click the fly-out menu button.
And you can see that one of the quick options 
here is a Two Period Moving Average. 
So I'll click on Two Period Moving Average and a 
Two Period Moving Average Trendline is added 
to the chart. 
This time the analysis shows that, for the first 
time in 10 years, 2008 was the year to sell up,
because the price has moved below the moving 
average for the first time. 
All that remains is to save your work.
And I'll save with the new name: UK House 
Prices-2. 
And as usual I'll save to the folder above my 
Sample Files Folder. 
I click the Save button and you've now 
completed Lesson 5-25: Add a Trendline.
