Introduction:
The coefficient of concurrent deviation is a measure of the relationship between two variables. It indicates how closely the variables move together in the same direction. In other words, it measures the extent to which the two variables deviate from their means in the same direction.

Calculation of Coefficient of Concurrent Deviation:
To calculate the coefficient of concurrent deviation, we need to determine the sum of the products of the deviations of the paired observations from their means.

Step 1: Calculate the mean of the paired observations:
Calculate the mean of the first variable (X) and the mean of the second variable (Y) from the given 10 pairs of observations.

Step 2: Calculate the deviations of the paired observations from their respective means:
Find the deviation of each observation in the X variable from the mean of X and the deviation of each observation in the Y variable from the mean of Y.

Step 3: Calculate the sum of the products of the deviations:
Multiply each deviation in X with the corresponding deviation in Y for each pair of observations, and sum up these products.

Step 4: Calculate the coefficient of concurrent deviation:
Divide the sum of the products of the deviations by the product of the standard deviations of X and Y.

Example Calculation:
Let's consider a specific example to illustrate the calculation of the coefficient of concurrent deviation.

Given:
Number of pairs of observations (n) = 10
Number of concurrent deviations (c) = 4

In this example, we are given the number of concurrent deviations, which is 4. However, we need additional information such as the actual values of the paired observations and their means to calculate the coefficient of concurrent deviation.

Conclusion:
To determine the value of the coefficient of concurrent deviation, we need to calculate the mean of the paired observations, the deviations of the observations from their means, and the sum of the products of the deviations. Without this information, it is not possible to calculate the coefficient of concurrent deviation.