y = -1E-08x6 + 7E-07x5 + 9E-05x4 - 0.008x3 + 0.1x2 + 2.0089x + 34.187

y = -1E-08x6 + 7E-07x5 + 9E-05x4 - 0.008x3 + 0.1x2 + 2.0089x + 34.187

this equatoin was calculated useing excels trendline thingy

the graph was calculated from this set of data

1 36
2 39
3 41
4 43
5 46
6 48
7 51
8 53
9 55
10 57
11 59
12 61
13 63
14 64
15 65
16 66
17 67
18 67
19 67
20 67
21 67
22 66
23 66
24 64
25 63
26 62
27 60
28 58
29 56
30 54
31 52
32 50
33 47
34 45
35 42
36 40
37 38
38 35
39 33
40 31
41 29
42 27
43 25
44 24
45 23
46 21
47 21
48 20
49 20
50 20
51 20
52 20
53 21
54 24
55 25
56 26
57 28
58 30
59 32


when i try to use the eqaution i test a x value like 30 and it gives me a number in the hundreds while the data chart had 30 as returning a y of 54 the equation seems to work better the closer it is to zero

the r^2 value is .9996 so the answer should be much more acuret than that

im not shure if its me or excel but something is wrong

i attached the excel sheet

thanks for the help
nate

Are you sure that is the right equation?

You see, if all the terms are positive like that, then every value must be > 34.187 for all x>0

However, looking at your data, esp. at the values for x = 40 to 59, this is not the case, so the r^2 value can't be right.

Perhaps a few of the coefficients are negative...i dunno

can u post a picture of the graph?