( 9 points) The following are contents of Vitamin C in micro-grams measured from 25 randomly selected Vitamin C chewable tablets produced by Brand A. 346,372,351,354,362,390,386,396,391,370,365,372,362,348,391,369,367,398,366, 379,385,397,374,350,383 (a) ( 2 points) Calculate the sample mean x. (b) ( 2 points) Calculate the sample standard deviation . (c) ( 2 points) Calculate the sample median value. (d) (3 points) Determine the proportion of the data values that lie within x1.5 and compare the result with the lower bound from Chebyshev's inequality. *For (a) and (b), please round your results to 2 decimal places..