Finding the Fourth Proportional to 81,785.10, 122,681.70 and 42,419.10

Step by Step Solution

1. Step 1: Write the proportion equation
   81,785.10 : 122,681.70 = 42,419.10 : x
2. Step 2: Convert to fraction form
   81,785.10/122,681.70 = 42,419.10/x
3. Step 3: Cross multiply
   81,785.10x = 122,681.70 × 42,419.10
4. Step 4: Simplify right side
   81,785.10x = 5,204,047,300.47
5. Step 5: Solve for x
   x = 5,204,047,300.47/81,785.10
6. Step 6: Final answer
   x = 63,630.75