What is the probability of flipping a coin 85 times getting tails 30 times or fewer, round your answer to the nearest 10th of a percent.

Given tan∅=4/3 and π< ∅< (3π)/2; find cos2∅ a. -24/25 b. 24/25 c. -24/7 d. -7/25

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?

Solve the given system of equations. 2y= -x+9 , 3x-6= -15