Finding the Fourth Proportional to 13,318.88, 19,978.47 and 3,457.55

Step by Step Solution

1. Step 1: Write the proportion equation
   13,318.88 : 19,978.47 = 3,457.55 : x
2. Step 2: Convert to fraction form
   13,318.88/19,978.47 = 3,457.55/x
3. Step 3: Cross multiply
   13,318.88x = 19,978.47 × 3,457.55
4. Step 4: Simplify right side
   13,318.88x = 69,076,608.89
5. Step 5: Solve for x
   x = 69,076,608.89/13,318.88
6. Step 6: Final answer
   x = 5,186.37