Finding the Fourth Proportional to 13,710.98, 18,921.21 and 7,742.72

Step by Step Solution

1. Step 1: Write the proportion equation
   13,710.98 : 18,921.21 = 7,742.72 : x
2. Step 2: Convert to fraction form
   13,710.98/18,921.21 = 7,742.72/x
3. Step 3: Cross multiply
   13,710.98x = 18,921.21 × 7,742.72
4. Step 4: Simplify right side
   13,710.98x = 146,501,631.09
5. Step 5: Solve for x
   x = 146,501,631.09/13,710.98
6. Step 6: Final answer
   x = 10,684.99