@Carl Love 

@Carl Love 


Sorry! I thought something was wrong about it.

[50, 0.24623131e-1], [150, 0.30492576e-1], [250, 0.37921405e-1], [350, 0.41231232e-1], [450, 0.48429132e-1], [550, 0.53879065e-1], [650, 0.63028417e-1], [750, 0.7402681e-1], [850, 0.84360848e-1], [950, 0.93120204e-1], [1050, .109879577], [1150, .125467687], [1250, .143243543], [1350, .163460496], [1450, .180390724], [1550, .198975116], [1650, .212349613], [1750, .241651973], [1850, .26603949], [1950, .274659312], [2050, .302078022]

@Carl Love 

Yes I am trying to dsiplay side by side, so I tried the array way:

and I got this error:

Error, unable to parse

@Carl Love thanks for the help!

@Carl Love 

I followed what you did and got this formula, is this correct?

Data := [[.158, 0.2e-1], [.159, 0.2e-1], [.161, 0.3e-1], [.164, 0.3e-1], [.166, 0.3e-1], [.169, 0.4e-1], [.173, 0.6e-1], [.178, 0.8e-1], [.185, .1], [.187, .11], [.193, .14], [.2, .19], [.21, .28], [.223, .38], [.233, .44], [.244, .58], [.256, .82], [.278, 1.4], [.281, 1.71], [.282, 1.78], [.282, 1.78], [.282, 1.81]];
X := Data[() .. (), 1];
Y := Data[() .. (), 2];
f := a+b*x^c+d*x^e;
Statistics:-NonlinearFit(f, X, Y, x);
print(`output redirected...`); # input placeholder
               

@Carl Love it gave me this output

Error, (in Statistics:-NonlinearFit) invalid input: PostProcessData expects its 1st argument, x, to be of type {array, list, rtable}, but received w

I am so sorry I gave you guys the wrong data points, The data points are reversed.

[[.158, 0.2e-1], [.159, 0.2e-1], [.161, 0.3e-1], [.164, 0.3e-1], [.166, 0.3e-1], [.169, 0.4e-1], [.173, 0.6e-1], [.178, 0.8e-1], [.185, .1], [.187, .11], [.193, .14], [.2, .19], [.21, .28], [.223, .38], [.233, .44], [.244, .58], [.256, .82], [.278, 1.4], [.281, 1.71], [.282, 1.78], [.282, 1.78], [.282, 1.81]]

I did:

> xlist := [.158, .159, .161, .164, .166, .169, .173, .178, .185, .187, .193, .2, .21, .223, .233, .244, .256, .278, .281, .282, .282, .282];> ylist := [0.2e-1, 0.2e-1, 0.3e-1, 0.3e-1, 0.3e-1, 0.4e-1, 0.6e-1, 0.8e-1, .1, .11, .14, .19, .28, .38, .44, .58, .82, 1.4, 1.71, 1.78, 1.78, 1.81, 1.82];print(??); # input placeholder>

> xylist := zip(proc (x, y) options operator, arrow; [x, y] end proc, xlist, ylist);print(`output redirected...`); # input placeholder [[0.158, 0.02], [0.159, 0.02], [0.161, 0.03], [0.164, 0.03],

[0.166, 0.03], [0.169, 0.04], [0.173, 0.06], [0.178, 0.08],

[0.185, 0.1], [0.187, 0.11], [0.193, 0.14], [0.2, 0.19],

[0.21, 0.28], [0.223, 0.38], [0.233, 0.44], [0.244, 0.58],

[0.256, 0.82], [0.278, 1.4], [0.281, 1.71], [0.282, 1.78],

[0.282, 1.78], [0.282, 1.81]]
> f := a+b*x^c+d*x^e;
> sol[1] := DataFit(f, X, Y, x, evaluationlimit = 20000);
print(??); # input placeholder
> f1 := eval(f, sol[1]);

and I got this error: 

Error, invalid input: eval received DataFit(a+b*x^c+d*x^e, X, Y, x, evaluationlimit = 20000), which is not valid for its 2nd argument, eqns