Finding the Fourth Proportional to 123,609.71, 170,609.24 and 72,638.81

Step by Step Solution

1. Step 1: Write the proportion equation
   123,609.71 : 170,609.24 = 72,638.81 : x
2. Step 2: Convert to fraction form
   123,609.71/170,609.24 = 72,638.81/x
3. Step 3: Cross multiply
   123,609.71x = 170,609.24 × 72,638.81
4. Step 4: Simplify right side
   123,609.71x = 12,392,852,776.72
5. Step 5: Solve for x
   x = 12,392,852,776.72/123,609.71
6. Step 6: Final answer
   x = 100,257.93