Error in estimates?

[bibanul]

I might be off on this but I can't get it to calculate using the correct example you provided. Im comparing it against Excel TREND function. Here's the data array, 12 periods, equidistant:

0, 734000
1, 769900
2, 822450
3, 849950
4, 849950
5, 872000
6, 855000
7, 889500
8, 895000
9, 897000
10, 894500
11, 890000

If I estimate for x=24 I get 437977.98 while TREND in Excel gives me a plausible number of 922492.67.

var estimationInput = new Array();
estimationInput['x'] = new Array();
estimationInput['x'][0] = 24;
var estimateData = lyric.applyModel(estimationInput, lyric.buildModel(input));

What am I missing here?