I’m having trouble on number 4

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?

How do the number line graphs of the solutions sets of -23 > x and x-23 differ?

Can someone explain to me how to do