1. For every two marriages that occurred in the 1990s, there was one divorce. This means that the divorce rate is about 50%.

This is not true! Although, it is correct that in the United States during most of the 1990s, there were about two marriages for every divorce in a single year. But this does not mean that the divorce rate is 50% because the people getting married in a single year are not the same ones getting divorced. This is a very common error and it results from the fact that that Vital Statistics report the numbers of marriages and divorces for each year. It is easy to think that some type of divorce rate can be calculated from these numbers, but it can't be done.