Finding the Fourth Proportional to 123,421.67, 170,328.12 and 72,436.63

Step by Step Solution

1. Step 1: Write the proportion equation
   123,421.67 : 170,328.12 = 72,436.63 : x
2. Step 2: Convert to fraction form
   123,421.67/170,328.12 = 72,436.63/x
3. Step 3: Cross multiply
   123,421.67x = 170,328.12 × 72,436.63
4. Step 4: Simplify right side
   123,421.67x = 12,337,994,628.94
5. Step 5: Solve for x
   x = 12,337,994,628.94/123,421.67
6. Step 6: Final answer
   x = 99,966.19