Finding the Fourth Proportional to 42,720.77, 64,087.29 and 13,141.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,720.77 : 64,087.29 = 13,141.10 : x
2. Step 2: Convert to fraction form
   42,720.77/64,087.29 = 13,141.10/x
3. Step 3: Cross multiply
   42,720.77x = 64,087.29 × 13,141.10
4. Step 4: Simplify right side
   42,720.77x = 842,177,166.18
5. Step 5: Solve for x
   x = 842,177,166.18/42,720.77
6. Step 6: Final answer
   x = 19,713.53