Chlorinated hydrocarbons (mg/kg) found in samples of two species of fish in a lake are as follows: Perform a hypothesis test to determine whether there is a difference in the mean level of...

Chlorinated hydrocarbons (mg/kg) found in samples of two species of fish in a lake are as follows:

Perform a hypothesis test to determine whether there is a difference in the mean level of hydrocarbons between the two species, assuming the population variances are equal. Is the equal variance assumption reasonable?