Please help with the question below

Alexander Borbely is a professor at the University of Zurich Medical School, where he is director of the sleep laboratory. The histogram in the figure below is based on information from his book Secrets of Sleep. The histogram displays hours of sleep per day for a random sample of 200 subjects. Estimate the mean hours of sleep, standard deviation of hours of sleep and coefficient of variation. (Enter x to 1 decimal place, s and CV to 2 decimal places.) Frequency T 06 90 80 70 64 60 50 40 30 27 20 _ 14 10 2 2 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 Hours of sleep