Amy wants to make two of her favorite cookie recipes for a party. One recipe needs 1 1/2 cups of flour and the other recipe needs 2 3/4 cups of flour. How much flour does Amy need? Please 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?