Private industry reported that more than 31,000 workers were absent from work in 2005 because of carpal tunnel syndrome (a nerve disorder causing arm, wrist, and hand pain). The length of time (in days) workers are absent as a result of this problem varies greatly.

Days of Absence, x 0–10 10–20 20–30 30–40 40–50 Number of Workers, f 37 24 38 32 27 Find the mean and the standard deviation for this distribution.