Question 12 Which of the following statements is true? I\" a. P'ie charts can only be used for nominal data. I\" b The median is a better measure of centre than the mean when the distribution is . symmetric. r\" c. Both data sets will have the same variance when two data sets have the same range I\" d Leading questions must be avoided in designing a questionnaire. r\" e in a histogram, the proportion of the total area to the left of the median is less than 50% {15 points