I need Help please???

Write an explicit formula that represents the sequence defined by the following recursive formula:

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?

Three friends are comparing the prices of various packages of golf balls at a sporting goods store. hector finds a package of 6 golf balls that costs $4.50.