Finding the Fourth Proportional to 30,568.72, 42,192.34 and 18,638.64

Step by Step Solution

1. Step 1: Write the proportion equation
   30,568.72 : 42,192.34 = 18,638.64 : x
2. Step 2: Convert to fraction form
   30,568.72/42,192.34 = 18,638.64/x
3. Step 3: Cross multiply
   30,568.72x = 42,192.34 × 18,638.64
4. Step 4: Simplify right side
   30,568.72x = 786,407,836.02
5. Step 5: Solve for x
   x = 786,407,836.02/30,568.72
6. Step 6: Final answer
   x = 25,725.90