How to detrend time series, and how to use moving average

Hey.
I'm new to this forum and I'm also a noob at Excel, so I struggle with some problems which may be simple for you but hard for me.

I am supposed to detrend a time series (excel file of the time series is attached, but I have no clue how to do it.
I am also supposed to use a moving average of the values but this is also something I don't understand how to do.

These problems have bugged me for several hours now so I would be very thankful if someone knew how to solve them. I also have more questions regarding the time series but I think it would be enough to start with these to questions. Below I have added the teachers explanation (which I did not understand), if it makes it easier for you to understand what I mean.

Thank you.


"First detrend the unemployment series. For the unemployment series, we will use a moving average of the previous 21 quarters values. That is use excel’s “=average(b1:b22) to obtain the trend value for quarter 23. Then drag the command down to find the rest of trend values. Take the difference from the actual value and you will have the percentage point deviation from trend. You should see a negative value during recessions."

Hi,

I am not 100% sure what you may be looking for.

I believe that I have added the formula's as you discribed and achieved a Trend Value.

However, I am unsure about the Quarters 21 and 23 you refered to.

Anyway see if this helps any.

Cheers

TonyB