Finding the Fourth Proportional to 42,480, 63,727.29 and 12,900.83

Step by Step Solution

1. Step 1: Write the proportion equation
   42,480 : 63,727.29 = 12,900.83 : x
2. Step 2: Convert to fraction form
   42,480/63,727.29 = 12,900.83/x
3. Step 3: Cross multiply
   42,480x = 63,727.29 × 12,900.83
4. Step 4: Simplify right side
   42,480x = 822,134,616.01
5. Step 5: Solve for x
   x = 822,134,616.01/42,480
6. Step 6: Final answer
   x = 19,353.45