Finding the Fourth Proportional to 30,615.91, 42,269.88 and 18,686.16

Step by Step Solution

1. Step 1: Write the proportion equation
   30,615.91 : 42,269.88 = 18,686.16 : x
2. Step 2: Convert to fraction form
   30,615.91/42,269.88 = 18,686.16/x
3. Step 3: Cross multiply
   30,615.91x = 42,269.88 × 18,686.16
4. Step 4: Simplify right side
   30,615.91x = 789,861,740.86
5. Step 5: Solve for x
   x = 789,861,740.86/30,615.91
6. Step 6: Final answer
   x = 25,799.06