Aprofessor gives 3 tests and uses a weighted average to determine the final grades in his psychology class. the weights are as follows: test 1 = 30%, test 2 = 20%, and test 3 = 50%. if a student scores 95 on the first test, 70 on the second test, and 80 on the third test, what would be her final score?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?