2-3 When data are not normally distributed, researchers can sometimes transform their data to obtain values that more closely approximate a normal distribution. One approach to this is to take the logarithm of the observations.

The following numbers represent the same data described in Prob. 2-1 following log (base 10) transformation: 4.90, 4.11, 4.26, 4.88, 5.41, 4.15, 4.66, 3.83, 4.93, 3.10, 3.78, 4.70, 4.04, 4.13, 3.03, 5.70, 4.40, 3.82, 4.05, 4.14. Find the mean, median, standard deviation, and 25th and 75th percentiles of these concentrations. Do these data seem to be drawn from a normally distributed population? Why or why not?