Sat scores are normally distributed with a mean of 500 points and a standard deviation of 100 points. suppose you take the sat. several weeks later you receive your results which show you reached the 80th percentile for the math portion recalling that sat scores are always expressed as multiples of 10, how many points did you get on the test
a. 690
b. 600
c. 580
d. 85
e. 550

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?