figure 6.22 indicates that the distribution of resistivity has a long tail to the right and consequently we would expect the long transformation (or a similar transformation) to product a distribution that is closer to normal the natural log of resistivity is shown in column three of table 6.8 and the normal probability plot of the natural log of resistivity is shown in figure 6.23 clearly the log transformation has resulted in a new variable that is more nearly approximated by normal distribution than were the original resistivity measurement