Finding the Fourth Proportional to 12,990.51, 17,916.48 and 8,740.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,990.51 : 17,916.48 = 8,740.17 : x
2. Step 2: Convert to fraction form
   12,990.51/17,916.48 = 8,740.17/x
3. Step 3: Cross multiply
   12,990.51x = 17,916.48 × 8,740.17
4. Step 4: Simplify right side
   12,990.51x = 156,593,081.00
5. Step 5: Solve for x
   x = 156,593,081.00/12,990.51
6. Step 6: Final answer
   x = 12,054.42