t-Test. Papers Introduction to the t-Test (University of Leicester) Describes the conditions that must be met in order to use of the test.Z-test and t-test are basically the same, they compare between two means to suggest whether both samples come from the same population.
Anchorage gets 22 hours of daylight on the longest day of summer. On the shortest day of winter, there are still seven and a half hours of daylight.
Day, night, and twilight times in Anchorage today. Black is nighttime, light blue is daytime. The darker blue shadings represent the twilight phases during dawn (left) and dusk (right). Hover over the graph for more information.