1. The health of the bear population in Yellowstone National Park is monitored by periodic measurements taken from anesthetized bears. A sample of 54 bears gave a mean weight of 181.9 pounds. Assuming that the standard deviation for all bear weights in Yellowstone National Park is 12.8 pounds, use a 6% significance level to test the claim that the average weight of all bears in this park is more than 180 pounds.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?