I have the following dataset
5 338.45
6
7
8
9
10 350.75
11
12
13
14
15 380.70
I need to calculate the missing values by plotting a linear trend line between the values I know (5, 10 and 15)
I did that by doing (350.75-338.45)/6 = 2.05 then adding that between 5 and 10 so:
5 338.45
6 340.5
7 342.55
8 344.6
9 346.65
10 350.75
Then same between 10 and 15 by adding 4.99
10 350.75
11 355.74
12 360.73
13 365.72
14 370.71
15 380.70
My question is once all that is calculated, if I had new 5 and 15 values, how do I apply those same trendlines to it
I only have new 5 and 15, not the 10.
5 295.99
6
7
8
9
10
11
12
13
14
15 309.99
Any help appreciated, thanks in advance!