figure 3 shows a hplc chromatograph of an analyzed sample that contained 3-nitrophenol, benzophenone, butylparaben, ethylparaben, and ketoprofen. the hplc utilized a waters acquity beh c-18 column, with a length of 100 mm, and the mobile phase was 60% water and 40% acetonitrile. determine the number of plates, the height of equivalent theoretical plates, and the resolution of the elution from the chromatograph shown. (for the resolution calculation, use the peaks corresponding to 3-nitrophenol and benzophenone.)