Finding the Fourth Proportional to 42,760.68, 64,143.18 and 13,198.74

Step by Step Solution

1. Step 1: Write the proportion equation
   42,760.68 : 64,143.18 = 13,198.74 : x
2. Step 2: Convert to fraction form
   42,760.68/64,143.18 = 13,198.74/x
3. Step 3: Cross multiply
   42,760.68x = 64,143.18 × 13,198.74
4. Step 4: Simplify right side
   42,760.68x = 846,609,155.59
5. Step 5: Solve for x
   x = 846,609,155.59/42,760.68
6. Step 6: Final answer
   x = 19,798.78