What do you call the middle number in a data set when arranged either ascending or descending order?

A population is the whole set of items from which a data sample can be drawn; so a sample is only a portion of the population data.  Features of a sample are described by statistics.

Statistical methods enable us to arrange, analyse and interpret the sample data obtained from a population.  We gather sample data when it is impractical to analyse the population data as a smaller sample often allows us to gain a better understanding of the population without doing too much work or wasting precious time.

Measures of Central Tendency

We make inferences about a population from a sample set of observed values by finding the mean, median and mode.  The mean, median and mode are collectively known as measures of central tendency.


Mean

The mean (or average) of a set of values is defined as the sum of all the values divided by the number of values.  That is:

What do you call the middle number in a data set when arranged either ascending or descending order?


Example 1

The marks of five candidates in a mathematics test with a maximum possible mark of 20 are given below:

14     12     18     17     13

Find the mean value.

Solution:

What do you call the middle number in a data set when arranged either ascending or descending order?

So, the mean mark is 14.8


Median

The median is the middle value of the data set arranged in ascending order of magnitude.

E.g. the median of 3, 5 and 9 is 5 as it is the middle value.


Example 2

The marks of five candidates in a geography test for which the maximum possible mark was 20 are given below:

18     17     15     14     19

Find the median mark.

Solution:

Arrange the marks in ascending order of magnitude:

14     15     17     18     19

The third value, 17, is the middle one in this arrangement.

What do you call the middle number in a data set when arranged either ascending or descending order?


Note:

What do you call the middle number in a data set when arranged either ascending or descending order?


In general:

What do you call the middle number in a data set when arranged either ascending or descending order?

If the number of values in the data set is even, then the median is the average of the two middle values.


Example 3

Find the median of the following scores:

10     16     14     19     8     11

Solution:

Arrange the values in ascending order of magnitude:

8     10     11     14     16     19

There are 6 values in the data set.

What do you call the middle number in a data set when arranged either ascending or descending order?

What do you call the middle number in a data set when arranged either ascending or descending order?

The third and fourth values, 11 and 14, are in the middle.  That is, there is no one middle value.

What do you call the middle number in a data set when arranged either ascending or descending order?


Note:

Half of the values in the data set lie below the median and half lie above the median.


Mode

The mode is the value (or values) that occurs most often.

E.g. the mode of the data set {3, 5, 6, 7, 7, 7, 8, 8, 9} is 7 as it occurs most often.


Example 4

The marks awarded to seven pupils for an assignment were as follows:

18     14     18     15     12     19     18

a.  Find the median mark.
b.  State the mode.

Solution:

a.  Arrange the marks in ascending order of magnitude:

12     14     15     18     18     18     19

What do you call the middle number in a data set when arranged either ascending or descending order?
Note:

The fourth mark, 18, is the middle data value in this arrangement.

What do you call the middle number in a data set when arranged either ascending or descending order?


b.  18 is the mark that occurs most often.

What do you call the middle number in a data set when arranged either ascending or descending order?


Note the following:
  • The mode has applications in manufacturing.  For example, it is important to manufacture more of the most popular cars, because manufacturing different cars in equal numbers would cause a shortage of some cars and an oversupply of others.
  • The mean (or average) of a set of data values is used to predict future results.
  • The median is easy to comprehend.  Extreme values in the data set do not affect the median.

Key Terms

statistics, population, sample, measures of central tendency, mean, average, median, mode

What do you call the middle number in a data set when arranged either in ascending or descending order * 1 point a range B mean C median D mode?

The median of a set of numbers is the middle number in the set (after the numbers have been arranged from least to greatest) -- or, if there are an even number of data, the median is the average of the middle two numbers. Example 1 : Find the median of the set {2,5,8,11,16,21,30} .

What is it called when the data is arranged in ascending or descending order the middle value in set of observations?

The middle most observation, after arranging all observations in ascending or descending order, is called the median.

What is called to arrange data in ascending and descending order?

Sorting is the process of arranging data in in ascending or descending order on the basis of one or more columns.

What is the middle number when the number in a set of data is arranged in descending order?

The median of a data set is the middle value when the values are written in numerical order. If a data set has an even number of values, the median is the mean of the two middle values.