Use the z-table, in the appendix of the textbook or in the file listed inModule 8, for the following questions:

1. What percentage of observations from a standard normal distribution are below a z-value of -2.15?
2. What percentage of observations from a standard normal distribution are above a z value of -2.15?
3. What percentage of observations from a standard normal distribution are above a z value of 2.15?
4. What percent of observations from a standard normal distribution are between -2.15 and 2.15?
5. Based on your answers to the above questions, list two facts that you notice about the standard normal distribution. Each fact is worth 2 points. (Please write your answer in complete sentences.)

The average number of milligrams of sodium in a certain low-salt microwave frozen dinners is 540 mg, and the standard deviation is 35 mg. Assume the variable is normally distributed.

1. If a single dinner is selected, find the probability that the sodium content will be more than 550 mg.
2. If a sample of 10 dinners is selected , find the probability that the mean of the sample will be larger than 550 mg.
3. Why is the probability for question #6 is greater than that for question #7. (Please write your answer in complete sentences.)