Question

For the first 7 months of the year, the average precipitation is toledo, ohio, is 19.32 inches. if the average precipitation is normally distributed with a standard deviation of 2.44 inches, find these probabilities: a randomly selected year will have precipitation greater than 18 inches for the first 7 months.

Answer 1

Answer: The correct answer is 70.54%.

The first thing to do is find the z-score for precipitation over 18 inches. You have to subtract the value from the mean and divide by the standard deviation.

18 - 19.32 = -1.32 / 2.44 = -0.54

Now, just look up the z-score of -0.54 on a standard normal distribution table and you will see that 29.46% of the scores are below 18 inches. Therefore, there are 70.54% scores above 18 inches.