The deciles of any distribution are the 10th, 20th, … , 90th percentiles. The first and last deciles are the 10th and 90th percentiles, respectively.

(a) What are the first and last deciles of the standard Normal distribution?
(b) The weights of 9-ounce potato chip bags are approximately Normal with mean 9.12 ounces and standard deviation 0.15 ounce. What are the first and last deciles of this distribution?

Question

The deciles of any distribution are the 10th, 20th, … , 90th percentiles. The first and last deciles are the 10th and 90th percentiles, respectively.

(a) What are the first and last deciles of the standard Normal distribution?
(b) The weights of 9-ounce potato chip bags are approximately Normal with mean 9.12 ounces and standard deviation 0.15 ounce. What are the first and last deciles of this distribution?

kropot72 · Answer

(a) A standard normal distribution table can be used to find the z-scores corresponding to the first and last deciles of the standard normal distribution. Find the z-scores for cumulative probability values of 0.1000 and 0.9000.