For 170 worms of a particular species, the mean and standard deviation of length of the worms were found to be 6.2 cm and 0.8 cm, respectively.

For 170 worms of a particular species, the mean and standard deviation of length of the worms were found to be 6.2 cm and 0.8 cm, respectively. Test if the observed mean is significantly greater than 6 cm using a level of significance α = 0.05.