Data Processing

The measure of central tendency that does not get affected by extreme values is the median. In the chapter, median is described as a positional average, so very large or very small values do not change it much. Therefore, the correct option is (d) Median.

The measure of central tendency that always coincides with the hump of any distribution is the mode, because it is the value that occurs most frequently. The chapter says the score with the highest frequency occurs in the middle of a normal distribution and this is the mode. So the correct option is (d) Mode.

The mean is the simple arithmetic average of the different values of a variable. To find it, we add all the observations and divide by the number of observations. In formula form, for ungrouped data, $$\bar{X} = \frac{\sum x}{N}$$ where $\sum x$ is the sum of all values and $N$ is the number of values.