What is the solution of the following system
x-y=11
-x+y=-11

Every time you drive you will experience a combination of driving conditions and environments.

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?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?