Finding the Fourth Proportional to 21,185.81, 29,233.36 and 13,642.37

Step by Step Solution

1. Step 1: Write the proportion equation
   21,185.81 : 29,233.36 = 13,642.37 : x
2. Step 2: Convert to fraction form
   21,185.81/29,233.36 = 13,642.37/x
3. Step 3: Cross multiply
   21,185.81x = 29,233.36 × 13,642.37
4. Step 4: Simplify right side
   21,185.81x = 398,812,313.46
5. Step 5: Solve for x
   x = 398,812,313.46/21,185.81
6. Step 6: Final answer
   x = 18,824.50