Given:
- 5/6, 5, 30, X are in proportion

To find:
- The value of X

Solution:
To solve this problem, we can use the concept of cross multiplication.

1. Cross multiply the first and second numbers:
5/6 * 30 = 5 * X

2. Simplify the equation:
150/6 = 5X

3. Multiply both sides of the equation by 6 to eliminate the fraction:
25 = 5X

4. Divide both sides of the equation by 5 to solve for X:
X = 25/5

Answer:
The value of X is 5.

Explanation:
The given numbers 5/6, 5, 30, and X are in proportion, which means that the ratio of any two consecutive numbers is equal to the ratio of the other two consecutive numbers.

In this case, the ratio between 5/6 and 5 is the same as the ratio between 5 and 30. Therefore, we can set up the proportion:

5/6 : 5 = 5 : 30

To solve for X, we can cross multiply the terms:

(5/6) * 30 = 5 * X

Multiplying the fractions and simplifying:

150/6 = 5X

To eliminate the fraction, we can multiply both sides of the equation by 6:

(150/6) * 6 = 5X * 6

Simplifying:

150 = 30X

Finally, divide both sides of the equation by 5 to solve for X:

X = 150/5

Therefore, the value of X is 5.