1. Along with the statistics it usually collects, the U.S. Census Bureau occasionally experiments by asking new demographic questions on a smaller scale (i.e. not across the entire U.S.). In 2014, the U.S. Census Bureau asked 12,000 households "How many dogs are in your household?" Based on the sample they reported a 90% confidence interval of: 1.93 +/- 0.02 What was their sample standard deviation?