forecast from last two values

[Abishy]

am using forecast to tell me a value for a trend of two values.Forecast(x,known y,known x) x is the current date on column A,Known y should be an array of last two values in column F from current date(what am looking for)known x is all the date in column A matching known y.
Please help

 

[Hui]

Abishy

Firstly, Welcome to the Chandoo.org Forums

To start with

1. There is no data in Column F or G

2. Column A is Text not Dates
Select A2:A66
Goto the Data, Text to Columns Tab
Select Delimitered, Next
Next
On Step 3 or 3
Select Date and select YMD, Finish

3. H15: =FORECAST(A15,E4:E12,A4:A12)

 

[Abishy]

hui thanks for replying in column F and G that's where the forecast values will be.l have put results manually l want with in column G. G15:=FORECAST(A15,use cells containing last two values i.e E12:e15,A12:A15)

 

[Abishy]

in other words the FORECAST should just calculate using last two values in column G

 

[Abishy]

 

[Abishy]

to illustrate this is where the excel data is coming from column A2:A66 are the dates on x-axis,B2:B66 are high points. Column D identifies points D57,D47.D40,D35,D32,D27 AND D23.if trend lines are drawn between two last points as shown, column F should calculate the points on this lines i.e. F58,F56,F44,F24.what formulate can be insert in column F to pick last two values in column D and "draw a trendline" on these two points thus forecast values with corresponding blank cells on column D?