If each score in a set of data scores were increased by 8 points, how would this affect the mean and the standard deviation?

A)The mean would increase by 8, and the standard deviation would increase by 8. B)The mean would increase by 8, but the standard deviation would increase by 64. C)The mean would increase by 8, and the standard deviation would remain the same. D)The mean would remain the same, and the standard deviation would increase by 8.
It's on usatestprep please help

In need of in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.

What is the solution to the division problem below x3+x2-11x+4/x+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?