Answer:

To calculate the mean (\(\bar{X}\)), you sum up all the values and then divide by the number of values (n).

In this case, you have \(D = x - 140\) and \(D = 500\), and \(n = 10\).

So, the sum of the values would be \(500 \times 10 = 5000\).

The mean (\(\bar{X}\)) is then calculated by dividing the sum by the number of values:

\[\bar{X} = \frac{5000}{10} = 500\]

Therefore, the mean of the given values is 500.