Finding the Fourth Proportional to 42,643.91, 63,978.15 and 13,066.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,643.91 : 63,978.15 = 13,066.10 : x
2. Step 2: Convert to fraction form
   42,643.91/63,978.15 = 13,066.10/x
3. Step 3: Cross multiply
   42,643.91x = 63,978.15 × 13,066.10
4. Step 4: Simplify right side
   42,643.91x = 835,944,585.82
5. Step 5: Solve for x
   x = 835,944,585.82/42,643.91
6. Step 6: Final answer
   x = 19,602.91