Finding the Fourth Proportional to 11,978.87, 16,535.93 and 8,531.69

Step by Step Solution

1. Step 1: Write the proportion equation
   11,978.87 : 16,535.93 = 8,531.69 : x
2. Step 2: Convert to fraction form
   11,978.87/16,535.93 = 8,531.69/x
3. Step 3: Cross multiply
   11,978.87x = 16,535.93 × 8,531.69
4. Step 4: Simplify right side
   11,978.87x = 141,079,428.62
5. Step 5: Solve for x
   x = 141,079,428.62/11,978.87
6. Step 6: Final answer
   x = 11,777.36