I need help with this question

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?

During a wright loss challenge your friend goes from 125 pounds to 100 pounds. what was the percent weight loss

Find an equation of the line that has intercepts (1,0) and (0,4).