What is 330mi/6hr as a rate

This is the number of parts out of 100, the numerator of a fraction where the denominator is 100. submit

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?

Which one is true about the hexagons ?