Lots of new policies get written every year, and millions of dollars get paid out on existing policies. They really need to know who's going to die and when. Before drug companies spend millions of dollars distributing and marketing new cancer drugs, they need to know exactly how effective those drugs are. And before they get the green light from government, they have to prove to the government that they know. They can get both these things after statistical analysis of the results of field trials on many humans.
Statistical analysis is worth a lot of money to the drug companies.
Teaching One of the most important jobs in our society is teaching. With a degree in Math you could teach Math in high school. There is currently a national shortage of Math teachers. With a PhD, you are able to teach Math at a University.