A clinical trial is performed to test a new drug designed to lower blood cholesterol levels. One hundred fifty participants are randomly assigned to take the new drug, and 150 participants are randomly assigned to take a placebo. After 6 months of treatment, blood cholesterol levels are measured and compared to the starting levels. For those who took the new drug, the blood cholesterol levels had a mean reduction of 35 points with a standard deviation of 4.1, while for those who took the placebo, the blood cholesterol levels showed a mean reduction of 27 points with a standard deviation of 2.9. Assuming the standard deviations are true for the entire population, calculate 90% confidence intervals and evaluate whether there is evidence the new drug is working.