A factory makes components used in jet engines, including reinforced steel washers. the washers are required to have a very precise thickness. the thickness of the washers follow a normal distribution with mean 1.59 millimeters and standard deviation 0.042 millimeters. a technician randomly samples washers and calculates the mean of their thicknesses, which is . what is the probability that ?

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome