The mean of the numbers 15,21,17,26,18 and 29 is 21. Calculate the standard deviation.

How many glue sticks are in a basket containing 96 scissors, if the ratio of glue sticks to scissors is 19 to 57.

Rewrite 9 log, x2 in a form that does not use exponents. 9log, x = log, x

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?