Finding the Fourth Proportional to 12,931.40, 17,844.86 and 7,904.05

Step by Step Solution

1. Step 1: Write the proportion equation
   12,931.40 : 17,844.86 = 7,904.05 : x
2. Step 2: Convert to fraction form
   12,931.40/17,844.86 = 7,904.05/x
3. Step 3: Cross multiply
   12,931.40x = 17,844.86 × 7,904.05
4. Step 4: Simplify right side
   12,931.40x = 141,046,536.94
5. Step 5: Solve for x
   x = 141,046,536.94/12,931.40
6. Step 6: Final answer
   x = 10,907.29