Question

center

1. What are the 3 measures of “center”? Describe each one.
2. What is an outlier? Which measure of center would we use if there are outliers in our data set?
3. Why would we use the mean instead of the median?

Answer 1

There are main three measures of central tendency i.e. mean, median and mode. Each of these measures describes a different indication of the typical or central value in the distribution.

Mean describe the Average value of the data Set. It can be used with both discrete and continuous data, although its use is most often with continuous data.

e.g Suppose we want find out the percentage of students in their last academic year .

Median describes the middle value of the data Set.The median divide the data into to equal parts (i.e. 50 - 50 %). The mode is the most frequent score in our data set. On a histogram it represents the highest bar in a bar chart or histogram.

Mode Describe the Most repeated value in the data set. A set of numbers may have one mode, more than one mode, or no mode at all.

Outliers= A value that lies outside (i.e. much smaller or larger than) than the other values in a set of data.

e.g

In this set of random numbers, 5 and 300 are outliers:
5, 99, 75, 70, 90, 89, 95, 300
5 is an extremely low value and 300 is an extremely high value.

The median is usually preferred in these situations because the value of the mean can be distorted by the outliers. Because the mean can be extremely affected by the outliers as compare to median.

Why would we use the mean instead of the median?

e.g Suppose you want to find out the average salary of the employ or the average marks of the students in that case we use mean over median because is good representative of the data set as compare to the median.