Central Tendancy

Central Tendency is defined as being a statistical measure that identifies a single score as representative of an entire distribution. It is measured via three mathematical terms we know as mean, median, and mode. The mean is basically the mathematical term for the average and is the most common measure of Central Tendency. The mean is the sum of all its values divided by the number of values. The median is the popular measure of central tendency. It is the 50th percentile of a distribution or the middle number. To determine the median one must first place the values in numerical order and then choose the middle number. Sometimes there are two middle values, and in that case, you would simply find the average of the two. The mode is the value which occurs the most in the distribution. This is the value that you would see more often than the others.

A skewed distribution is one in which there is a long tail on one side of the distribution. It is defined as being an “asymmetrical” distribution of values. There are two types of skewed distributions, positive and negative. In a positive skew, there is a long tail to the right and in a negative skew; there is a long tail to the left.

In a normal distribution the mean of the set of values 5, 4, 5 and 10 would be 6. The median of these values in this distribution would be 5. The mode in this distribution would also be 5.

In a positively skewed distribution, the mean isn’t a useful measure to use, the median is. In this type of distribution, one would find that the mean would be the largest value hence making the median and mode less than the mean.

In a distribution where the mean is 100 and the standard deviation is 15, it is basically telling us that the majority of the values are either plus or minus 15 points away from the mean.

An individual who is in group I which has a means of 100 can have a higher score than the mean score of group II