Finding the Fourth Proportional to 30,879.72, 42,597.90 and 18,945.72

Step by Step Solution

1. Step 1: Write the proportion equation
   30,879.72 : 42,597.90 = 18,945.72 : x
2. Step 2: Convert to fraction form
   30,879.72/42,597.90 = 18,945.72/x
3. Step 3: Cross multiply
   30,879.72x = 42,597.90 × 18,945.72
4. Step 4: Simplify right side
   30,879.72x = 807,047,885.99
5. Step 5: Solve for x
   x = 807,047,885.99/30,879.72
6. Step 6: Final answer
   x = 26,135.21