Settlements in Egypt before the time of the pharaohs are dated by measuring the presence of forms of carbon that decay over time. The first datings of settlements in the Nagada region used hair that have been excavated 60 years earlier. Now researchers have used newer methods and more recently excavated material. Do the dates differ? Here is the conclusion about one location: "There are two dates from Site KH6. Statistically, the two dates are not significantly different. They provide a weighted average corrected date of 3715 ± 90 B.C." Explain to someone interested in ancient Egypt but not interested in statistics what "not significantly different" means. A social psychologist reports, "In our sample, ethnocentrism was significantly higher (P < 0.05) among church attenders than among non-attenders." Explain to someone who knows no statistics what this means.