Question

Suppose that the pH of soil samples taken from a certain geographic region is normally distributed with a mean pH of 5 and a standard deviation of 0.20. If the pH of a randomly selected soil sample from this region is determined and equal to x, answer the following questions about it.

(a)

What is the probability that the resulting pH is between 4.60 and 5.30? (Round your answer to four decimal places.)

(b)

What is the probability that the resulting pH exceeds 5.20? (Round your answer to four decimal places.)

(c)

What is the probability that the resulting pH is at most 4.90? (Round your answer to four decimal places.)

(d)

What value will be exceeded by only 15% of all such pH values? (Round your answer to two decimal places.)

You may need to use the appropriate table in the appendix or technology to answer this question.

Answer 1