Finding the Fourth Proportional to 12,961.72, 17,887.20 and 7,372.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,961.72 : 17,887.20 = 7,372.72 : x
2. Step 2: Convert to fraction form
   12,961.72/17,887.20 = 7,372.72/x
3. Step 3: Cross multiply
   12,961.72x = 17,887.20 × 7,372.72
4. Step 4: Simplify right side
   12,961.72x = 131,877,317.18
5. Step 5: Solve for x
   x = 131,877,317.18/12,961.72
6. Step 6: Final answer
   x = 10,174.37