Finding the Fourth Proportional to 81,620.74, 122,496.72 and 42,189.40

Step by Step Solution

1. Step 1: Write the proportion equation
   81,620.74 : 122,496.72 = 42,189.40 : x
2. Step 2: Convert to fraction form
   81,620.74/122,496.72 = 42,189.40/x
3. Step 3: Cross multiply
   81,620.74x = 122,496.72 × 42,189.40
4. Step 4: Simplify right side
   81,620.74x = 5,168,063,118.77
5. Step 5: Solve for x
   x = 5,168,063,118.77/81,620.74
6. Step 6: Final answer
   x = 63,318.01