20% of is 21. PLS 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?

Write an equation in point-slope form for the line through the given point that has the given slope (-2,-7); m=-3/2

Me n o w. i need t h i s. 10 points