A technician compares repair costs for two types of microwave ovens (type I and type II). He believes that the repair cost for type I ovens is greater than the repair cost for type II ovens. A sample of 60 type I ovens has a mean repair cost of $77.22, with a standard deviation of $22.46. A sample of 65 type II ovens has a mean repair cost of $73.73, with a standard deviation of $10.62. Conduct a hypothesis test of the technician's claim at the 0.1 level of significance. Let μ1 be the true mean repair cost for type I ovens and μ2 be the true mean repair cost for type II ovens.

Apopulation of deer mice was introduced into a desert ecosystem. being dark-colored, the deer mice stood out in the sand and were easy prey for predators. over a few years, the color of the mice changed from dark brown to light brown. what role does natural selection play in this example? a. the change of color camouflaged them, which them hunt better. b. the change of color enabled them to regulate their body temperature. c. the change of color allowed them to hide better from predators. d. the change of color made their bodies tolerant to the harsh desert sand. e. the change of color allowed them to deflect the excessive heat.