Finding the Fourth Proportional to 13,388.88, 18,476.64 and 7,420.56

Step by Step Solution

1. Step 1: Write the proportion equation
   13,388.88 : 18,476.64 = 7,420.56 : x
2. Step 2: Convert to fraction form
   13,388.88/18,476.64 = 7,420.56/x
3. Step 3: Cross multiply
   13,388.88x = 18,476.64 × 7,420.56
4. Step 4: Simplify right side
   13,388.88x = 137,107,015.72
5. Step 5: Solve for x
   x = 137,107,015.72/13,388.88
6. Step 6: Final answer
   x = 10,240.36