Factor 35y+40z 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?

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?