One of the important factors in auto safety is the weight of the vehicle. insurance companies are interested in knowing the average weight of cars currently licensed in the united states; they believe it is 3000 pounds. to see if that estimate is correct, they checked a random sample of 91 cars. for that group, the mean weight was 2919 pounds, with a standard deviation of 531.5 pounds. provide the: h0,ha, test statistic and approximate p-value. check all conditions and interpret your decision in the context of the claim. is this strong evidence that the mean weight of all cars differs from 3000 pounds at alpha= .01?

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?