[r] at a large university, a sample of 52 evening students was selected in order to determine whether the average age of the evening students is significantly different from 21. the average age of the students in the sample was 21.48 years. the sample standard deviation was 1.3 years. determine whether or not the average age of the evening students is significantly different from 21. use a 0.01 level of significance. choose the t-statistic and the appropriate conclusion. group of answer choices

Sum is 17 and their difference is 3

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?

On which number line are -3 and its opposite shown