Lionel takes four tests and scores the following marks. 65,72,58,77 (a) What are his median and mean scores? If he scores 70 in his next test, does his mean score increase or decrease? Find his new mean score. Which has increased most, his mean score or his median score?​

What is the value of the digit 1 in the number 13?

Evaluate the following expression 1/3^2

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?