Finding the Fourth Proportional to 30,557.79, 42,090.87 and 21,589.72

Step by Step Solution

1. Step 1: Write the proportion equation
   30,557.79 : 42,090.87 = 21,589.72 : x
2. Step 2: Convert to fraction form
   30,557.79/42,090.87 = 21,589.72/x
3. Step 3: Cross multiply
   30,557.79x = 42,090.87 × 21,589.72
4. Step 4: Simplify right side
   30,557.79x = 908,730,097.86
5. Step 5: Solve for x
   x = 908,730,097.86/30,557.79
6. Step 6: Final answer
   x = 29,738.08