Ummm please what is H im slow

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?

The complement of an angle is one-sixth the measure of the supplement of the angle. what is the measure of the complement angle?

Which of the following vectors are orthogonal to (2,1)? check all that apply