Final answer:
There is a discrepancy between measured and true wavelengths in a mercury spectral lines experiment. The issue lies in the formula application and measurement accuracy. The correct approach requires a reassessment of experimental values and formula use.
Step-by-step explanation:
The issue observed seems to be related to the calculation of the wavelengths of light emitted by mercury vapors using a diffraction grating in a physics laboratory experiment. The student has encountered discrepancies between measured and true values and is trying to understand the source of these inconsistencies.
To calculate the wavelengths, the formula being applied is λ=dsin(arctan((x/y))), with d representing the distance between the grating grooves, x as the average x-axis length, and y as the constant y-axis length. To correct the observed percent error of about 60%, it is necessary to reassess the experimental setup's constants, measurements, and the implementation of the formula.