Question: Having a baby in a US hospital costs $2528 on average. Active management of labor (AML) is a group of interventions designed to help reduce length of labor and rate of cesarean deliveries. Physicians from Department of Obstetrics and Gynecology were interested in determining whether AML would also translate into a reduced cost for delivery. The results of their study can be found in Rogers et al., “Active Managemnet of Labor: A Cost Analysis of a Randomized Controlled Trial”. According to the article, 200 AML deliveries had a mean cost of $2480 with a standard deviation of $766. At the 5 % significance level, does that data provide sufficient evidence to conclude that, on average, AML reduces the cost of having a baby in a US hospital?