Finding the Fourth Proportional to 42,781.38, 64,166.13 and 13,200.18

Step by Step Solution

1. Step 1: Write the proportion equation
   42,781.38 : 64,166.13 = 13,200.18 : x
2. Step 2: Convert to fraction form
   42,781.38/64,166.13 = 13,200.18/x
3. Step 3: Cross multiply
   42,781.38x = 64,166.13 × 13,200.18
4. Step 4: Simplify right side
   42,781.38x = 847,004,465.90
5. Step 5: Solve for x
   x = 847,004,465.90/42,781.38
6. Step 6: Final answer
   x = 19,798.44