Consider the fluorescence spectra image below. Assuming a linear relationship is preserved between signal intensity and concentration, estimate in micromolar units the lower limit concentration that would result in a S/N ratio of 5.0. Estimate the noise level to be 0.01 intensity units. Report your answer with only 2 decimal places.

Fluorescence 500 nm (Rel.) 1.0- 0.8- 0.6- 0.4- 0.2- 0.0- Fluorescence of Fluorescein and Phenolphthalein 500 Peak for Fluorescein at 515 nm 700 Wavelength (nm) Fluorescein (1ppm) | Fluorescence 500 nm Phenolphthalein (1ppm) | Fluorescence 500 nm 900