Finding the Fourth Proportional to 11,978.72, 16,528.44 and 9,101.60

Step by Step Solution

1. Step 1: Write the proportion equation
   11,978.72 : 16,528.44 = 9,101.60 : x
2. Step 2: Convert to fraction form
   11,978.72/16,528.44 = 9,101.60/x
3. Step 3: Cross multiply
   11,978.72x = 16,528.44 × 9,101.60
4. Step 4: Simplify right side
   11,978.72x = 150,435,249.50
5. Step 5: Solve for x
   x = 150,435,249.50/11,978.72
6. Step 6: Final answer
   x = 12,558.54