Finding the Fourth Proportional to 21,178.40, 31,760.91 and 7,667.82

Step by Step Solution

1. Step 1: Write the proportion equation
   21,178.40 : 31,760.91 = 7,667.82 : x
2. Step 2: Convert to fraction form
   21,178.40/31,760.91 = 7,667.82/x
3. Step 3: Cross multiply
   21,178.40x = 31,760.91 × 7,667.82
4. Step 4: Simplify right side
   21,178.40x = 243,536,940.92
5. Step 5: Solve for x
   x = 243,536,940.92/21,178.40
6. Step 6: Final answer
   x = 11,499.31