Questions about some results from Curve Fitting Tool

After using the Curve Fitting Tool, I get the following output:

----------------------------------
General model:
     f(x) = a*((x-3.4)^(1/2)*(1/(exp((x-3.4-2.92099 )/(8.6*10^(-5)*b))+1)))+c

Coefficients (with 95% confidence bounds):

         a =       -4243
         b =         300
         c =        1814  (1738, 1890)
Goodness of fit:

    SSE: 6748
    R-square: 0.9789
    Adjusted R-square: 0.9759
    RMSE: 21.95
  -----------------------------------

My questions are:

1. For coefficients a and b shown above, what is the meaning that the confidence bounds were not calculated?
2. Can I trust these numbers?

[Zain Mecklai]

By the way, we support markup for making ordered lists using the # symbol at the start of a new paragraph

Like this:

# Note the blank line above

# This would be item 2

Answer 1

[neha]

confidence bound can b changed...but by default.it takes d bound of 95%. and if your model get converged....plus u shud try to minimize RMSE value..it would be a better fit.