Since he was hired, a chef has served a total of 407 guests. Of those guests, 357 were adults. How many children has the chef served?

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?