Please help I don't know how to do this

Which expressions are equivalent to -6 + 3m

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?

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.