You have calibrated a GFAAS for the detection of chromium over the range of 1 ppb to 500 pb.
using the information given in the table below, calculate the concentration of an unknown that gave a signal of 6523 mv and report Sxo the 95% CL error bars.
Note that the standard error of the estimate, or Sy/x, is 173.8 and Sxx is 184,480