Finding the Fourth Proportional to 12,171.31, 18,259.40 and 5,151.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,171.31 : 18,259.40 = 5,151.31 : x
2. Step 2: Convert to fraction form
   12,171.31/18,259.40 = 5,151.31/x
3. Step 3: Cross multiply
   12,171.31x = 18,259.40 × 5,151.31
4. Step 4: Simplify right side
   12,171.31x = 94,059,829.81
5. Step 5: Solve for x
   x = 94,059,829.81/12,171.31
6. Step 6: Final answer
   x = 7,728.00