A  production manager claims that an average of 50 boxes per hour are filled with finished goods at a final stage of production line. A random sample of 48 different workers, at different times, working at the end of identical production lines an average number of  boxes filled as 47.5 with a standard deviation of  0.7 boxes. 

Does this evidence support  the  assertion by  the  production manager at the 1% level of significance ?