Finding the Fourth Proportional to 20,656.89, 28,496.01 and 13,491.00

Step by Step Solution

1. Step 1: Write the proportion equation
   20,656.89 : 28,496.01 = 13,491.00 : x
2. Step 2: Convert to fraction form
   20,656.89/28,496.01 = 13,491.00/x
3. Step 3: Cross multiply
   20,656.89x = 28,496.01 × 13,491.00
4. Step 4: Simplify right side
   20,656.89x = 384,439,564.05
5. Step 5: Solve for x
   x = 384,439,564.05/20,656.89
6. Step 6: Final answer
   x = 18,610.72