Finding the Fourth Proportional to 52,128.12, 78,191.52 and 12,685.32

Step by Step Solution

1. Step 1: Write the proportion equation
   52,128.12 : 78,191.52 = 12,685.32 : x
2. Step 2: Convert to fraction form
   52,128.12/78,191.52 = 12,685.32/x
3. Step 3: Cross multiply
   52,128.12x = 78,191.52 × 12,685.32
4. Step 4: Simplify right side
   52,128.12x = 991,884,452.49
5. Step 5: Solve for x
   x = 991,884,452.49/52,128.12
6. Step 6: Final answer
   x = 19,027.82