Question

A standard stock solution is diluted to generate three working standard solutions containing ethyl acetate (EA) at 50 ppm, 400 ppm, and 800 ppm. An internal standard, n-butanol (nB), is added so its concentration is 1500 ppm in each of the working standard solutions. The solutions are analyzed using GC-FID.

The peak area data for the peak corresponding to ethyl acetate from the standard chromatograms
50 ppm (EA area = 5.05, nB area = 124.37)
400 ppm (EA area = 47.98, nB area = 125.31)
800 ppm (EA area = 98.21, nB area = 130.63)

The results for the linear regression analysis for the data set using Excel are

It's one of these:

m = 1.4251, b = -0.003901
m = 1.4215, b = -0.003091
m = 0.7015, b = 0.002231
m = 0.7065, b = 0.002134