To find out the probability using normal distribution.

Many species of terrestrial tree frogs that hibernate at or near the ground surface can survive prolonged exposure to low winter temperatures. In freezing conditions, the frog's body temperature, called its super-cooling temperature, remains relatively higher due to an accumulation of glycerol in its body fluids. Recent studies have shown that the super-cooling temperature of terrestrial frogs frozen at -6°C has a relative frequency distribution with a mean of - 2°C and a standard deviation of 0.3°C (The first of these studies was reported in Science, May 1983.) Consider the mean super cooling temperature, x , of a random sample of n = 42 terrestrial frogs frozen at -6°C.

a. Find the probability that x exceeds -2.05°C.

b. Find the probability that x falls between -2.20°C and -2.10°C.