Finding the Fourth Proportional to 30,917.34, 42,658.79 and 20,864.43

Step by Step Solution

1. Step 1: Write the proportion equation
   30,917.34 : 42,658.79 = 20,864.43 : x
2. Step 2: Convert to fraction form
   30,917.34/42,658.79 = 20,864.43/x
3. Step 3: Cross multiply
   30,917.34x = 42,658.79 × 20,864.43
4. Step 4: Simplify right side
   30,917.34x = 890,051,233.52
5. Step 5: Solve for x
   x = 890,051,233.52/30,917.34
6. Step 6: Final answer
   x = 28,788.09