Finding the Fourth Proportional to 42,737.60, 64,082.88 and 13,147.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,737.60 : 64,082.88 = 13,147.20 : x
2. Step 2: Convert to fraction form
   42,737.60/64,082.88 = 13,147.20/x
3. Step 3: Cross multiply
   42,737.60x = 64,082.88 × 13,147.20
4. Step 4: Simplify right side
   42,737.60x = 842,510,439.94
5. Step 5: Solve for x
   x = 842,510,439.94/42,737.60
6. Step 6: Final answer
   x = 19,713.56