Steps in Hypothesis Testing: Videos & Practice Problems

A pharmaceutical company wants to determine if their new drug reduces cholesterol more effectively than a placebo. The reduction in cholesterol in milligrams per deciliter was measured after three months. The data are as follows: 

Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Use degrees of freedom equal to the smaller of $n_1-1$ and $n_2-1$. At the $0.05$ significance level, test the claim that the new drug leads to a greater mean reduction in cholesterol than the placebo.