Later in the paper we find out that 619 out of 7,329 men who got Vitamin C had a “major cardiovascular event” compared to 626 out of 7,312 men who got the placebo. We also read that the p-value for a difference in incidence rates is 0.91. Find the incidence rates, state the null and alternative hypotheses for a test of the effectiveness of Vitamin C, and draw inferences about the effectiveness of Vitamin C in preventing major cardiovascular events in this sample.

The Physicians’ Health Study II was a randomized, double-blind, placebo- controlled … trial of … vitamin C that began in 1997 and continued until its scheduled completion on August 31, 2007. There were 14,641 US male physicians enrolled, who were initially aged 50 years or older.