Two new drugs are being compared for effectiveness in lowering total cholesterol levels. On a sample of 10 subjects, drug A is found to lower cholesterol by an average of 65 mg/dl with SS=2025.On a sample of 15 subjects, drug B lowered the mean cholesterol level by 72 mg/dl with SS=2525. Use a 0.05 level of significance (2 tail test) to test the claim that the two drugs are equally effective. Assume that the population is normally distributed.

THE FIRST USE OF THE TERM SS IS TO DETERMINE THE VARIANCE

The null hypotheses (H₀) _______________