Eight randomly selected customers at a local grocery store spent the following amounts on groceries in a single visit: $216, $184, $35, $92, $142, $175, $9, and $57. Let yi denote the amount spent on groceries by a single customer in a single visit. Find the following (give the answers without commas): a. ∑y
b. (∑y)^2
c. ∑y^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?