10.102 Two different types of coating for pipes are to be compared with respect to their ability to aid in resistance to corrosion. The amount of corrosion on a pipe specimen is quantified by measuring the maximum pit depth. For coating A, 35 specimens showed an average maximum pit depth of 0.18 cm. The standard deviation of these maximum pit depths was 0.02 cm. For coating B, the maximum pit depths for 30 specimens had a mean of 0.21 cm and a standard deviation of 0.03 cm.
Do the mean pit depths appear to differ for the two types of coating? Use