Kind of confused, can someone help?

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?

If chord ab is congruent to chord cd, then what must be true about ef and eg?

Is of - 4x + 2? a. 3 b. 4 c. 6 d. 5