Finding the Fourth Proportional to 42,724.05, 64,087.10 and 13,142.16

Step by Step Solution

1. Step 1: Write the proportion equation
   42,724.05 : 64,087.10 = 13,142.16 : x
2. Step 2: Convert to fraction form
   42,724.05/64,087.10 = 13,142.16/x
3. Step 3: Cross multiply
   42,724.05x = 64,087.10 × 13,142.16
4. Step 4: Simplify right side
   42,724.05x = 842,242,856.43
5. Step 5: Solve for x
   x = 842,242,856.43/42,724.05
6. Step 6: Final answer
   x = 19,713.55