The kilowatt/hour (kWh) generated by a solar system of 12 panels from (12–1 p.m.), during the summer months, has a normal distribution with mean 2.25 and a standard deviation of 0.5. If 10 solar systems of this kind are randomly sampled, find
a) The probability that the sample average is 3 kWh or more.
b) The probability that the sample average is between 2.09 and 2.41 kWh.