Finding the Fourth Proportional to 31,340.32, 43,225.50 and 21,780.09

Step by Step Solution

1. Step 1: Write the proportion equation
   31,340.32 : 43,225.50 = 21,780.09 : x
2. Step 2: Convert to fraction form
   31,340.32/43,225.50 = 21,780.09/x
3. Step 3: Cross multiply
   31,340.32x = 43,225.50 × 21,780.09
4. Step 4: Simplify right side
   31,340.32x = 941,455,239.46
5. Step 5: Solve for x
   x = 941,455,239.46/31,340.32
6. Step 6: Final answer
   x = 30,039.75