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.
In the winter, the Interior gets about 4, maybe 4 1/2 hours of daylight. Barrow bids farewell to the sun entirely for about 6 weeks, and places like Anchorage or Juneau have around 6 or 7 hours of daylight. Again, for Barrow, though the sun technically never rises, there's still light around the edges of the horizon, so it's not pitch black 24/7. Hope that clears it up some.