A UCT marine biologist claims that the mean length of male harbour seals is greater than the mean length of female harbour seals. The mean length of a random sample of 89 male harbour seals is 132 centimetres. Assume the population standard deviation is 23 centimetres. The mean length of a random sample of 56 female harbour seals is 124 centimetres. Assume the population standard deviation is 18 centimetres. At = 0.05, can you support the marine biologist's claim?