Refer to Exercise 34. A random sample of six days is selected. Find the probability that the mean surface concentration of carbonyl sulfide for the sample is 

(a) Between 5.1 and 15.7 picomoles per liter, 

(b) Between 10.5 and 12.3 picomoles per liter, and 

(c) More than 11.1 picomoles per liter. Compare your answers with those in Exercise 34.

Find the indicated probabilities and interpret the results.

Data from exercise 34:

The daily surface concentration of carbonyl sulfide on the Indian Ocean is normally distributed, with a mean of 9.1 picomoles per liter and a standard deviation of 3.5 picomoles per liter. Find the probability that on a randomly selected day, the surface concentration of carbonyl sulfide on the Indian Ocean is 

(a) Between 5.1 and 15.7 picomoles per liter.

(b) Between 10.5 and 12.3 picomoles per liter.

(c) More than 11.1 picomoles per liter.