Coefficient of Mean Deviation about Mean for the First 9 Natural Numbers

Mean Deviation
The mean deviation is a measure of dispersion that measures the average deviation of a set of numbers from their arithmetic mean. Mean deviation is calculated as the arithmetic mean of the absolute deviations of the observations from the arithmetic mean of the data.

Coefficient of Mean Deviation
The coefficient of mean deviation is the ratio of the mean deviation to the mean of the data. It is also known as the mean absolute deviation ratio.

First 9 Natural Numbers
The first 9 natural numbers are 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Calculation of Mean
The mean of the first 9 natural numbers is calculated as follows:

Mean = (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9) / 9
Mean = 5

Calculation of Mean Deviation
The mean deviation of the first 9 natural numbers is calculated as follows:

Mean Deviation = (|1-5| + |2-5| + |3-5| + |4-5| + |5-5| + |6-5| + |7-5| + |8-5| + |9-5|) / 9
Mean Deviation = 4

Calculation of Coefficient of Mean Deviation
The coefficient of mean deviation of the first 9 natural numbers is calculated as follows:

Coefficient of Mean Deviation = Mean Deviation / Mean
Coefficient of Mean Deviation = 4 / 5
Coefficient of Mean Deviation = 0.8

Therefore, the coefficient of mean deviation about mean for the first 9 natural numbers is 0.8.