2-2 The Normal Distribution: Activity b. We again need software for this, either find the proportion closest to 0.9500 in the standard normal table and write the corresponding z-score type qnorm(0.95) in RStudio and write the result here c. Plug the z-score, mean, and standard deviation into the z-score formula and solve for x. d. This means that the 95th percentile of all fourth graders' scores is e. Repeat the steps above to find the 95th percentile of the second graders' scores.What if we are not given a score but instead asked what score marks a particular percentile? A percentile is a value from a distribution that has a specified percent of the population values below it. 10. To find the score that is the 95th percentile for all fourth graders, then we need the z-score that corresponds to 95% area to the left. a. Draw a normal distribution picture, and make a mark on the number line to represent the number with 95% of the area to the left, then shade that area. Learning Through Practice: Doing Statistics 49