Final answer:
The proportion of cockroaches with weights above, below, and equal to the mean depends on the shape of the weight distribution.
Step-by-step explanation:
The proportion of cockroaches with weights above the mean depends on the shape of the weight distribution. If the distribution is symmetric, then the proportion above the mean is the same as below the mean. If the distribution is skewed, then the proportion above the mean would be larger than below the mean.
The proportion of cockroaches with weights equal to the mean is usually very small, as it is unlikely for any individual to have exactly the mean weight. So, the answer to a) would be far less likely than, b) would be far less likely than, c) would be equally as likely as, and d) would be irrelevant to the mean.