Can somebody explain me about the numeric line? !

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?

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

Pls brainliest will be awarded if answer is correct