Finding the Fourth Proportional to 12,979.17, 17,918.15 and 10,398.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,979.17 : 17,918.15 = 10,398.86 : x
2. Step 2: Convert to fraction form
   12,979.17/17,918.15 = 10,398.86/x
3. Step 3: Cross multiply
   12,979.17x = 17,918.15 × 10,398.86
4. Step 4: Simplify right side
   12,979.17x = 186,328,333.31
5. Step 5: Solve for x
   x = 186,328,333.31/12,979.17
6. Step 6: Final answer
   x = 14,355.95