How to calculate the Linest

[#1]

I have the following Excel sheet:

Facility	Q1	Q2	Q3	Q4	2013 Average	Target	Trend
Bateen	92%	93%	90%	89%	91%	89%	Decreasing	-0.0099
Khaleej	92%	93%	93%	94%	93%	89%	Increasing	0.00766
Etihad	-	-	98%	94%	96%	89%	Decreasing
Rawda	92%	92%	95%	92%	92%	89%	Increasing	0.00362
Zafarana	86%	88%	85%	84%	86%	89%	Decreasing	-0.0089

=IF(LINEST(B40:E40)>0,"Increasing",IF(LINEST(B40:E40)<0,"Decreasing","Stable"))      => is used to calculate the Increase Decrease

= Avg(MeanTotal)     => this is the percentage shown

how can i apply this in Qlikview ( as formula ) to get if it increase or decrease in each Quarter

[#2]

Gysbert Wassenaar and Manish Kachhia can u please help in this. REALLY important for me and sure you can solve it