A rocket travels in a trajectory given by the equation s = -4.9t 2 + v0t, where s is meters above ground, t is time in seconds and v0 is the initial velocity. If the intial velocity is 49 m/sec, after how many seconds will the rocket reach its maximum height?

a 5
b 10
c 15

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?