Two chemicals x and y are to be mixed together to achieve a 16ml solution that is 7.4% water. chemical x is 5% water and y is 9% water. how much y should be used in the mix?

Which is the graph of f(x) = (4)x? image for option 1 image for option 2 image for option 3 image for option 4

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?

Why is causation so much more difficult to prove than correlation?