Finding the Fourth Proportional to 11,978.78, 17,946.27 and 8,683.70

Step by Step Solution

1. Step 1: Write the proportion equation
   11,978.78 : 17,946.27 = 8,683.70 : x
2. Step 2: Convert to fraction form
   11,978.78/17,946.27 = 8,683.70/x
3. Step 3: Cross multiply
   11,978.78x = 17,946.27 × 8,683.70
4. Step 4: Simplify right side
   11,978.78x = 155,839,935.07
5. Step 5: Solve for x
   x = 155,839,935.07/11,978.78
6. Step 6: Final answer
   x = 13,009.67