Finding the Fourth Proportional to 10,985.61, 16,470.59 and 5,139.03

Step by Step Solution

1. Step 1: Write the proportion equation
   10,985.61 : 16,470.59 = 5,139.03 : x
2. Step 2: Convert to fraction form
   10,985.61/16,470.59 = 5,139.03/x
3. Step 3: Cross multiply
   10,985.61x = 16,470.59 × 5,139.03
4. Step 4: Simplify right side
   10,985.61x = 84,642,830.43
5. Step 5: Solve for x
   x = 84,642,830.43/10,985.61
6. Step 6: Final answer
   x = 7,704.88