Which property states that for all real numbers, x, y and z, if x = y and y = z, then x = z ?

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?

What is the missing step in this proof ?

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12