Finding the Fourth Proportional to 30,828.02, 42,542.69 and 21,402.05

Step by Step Solution

1. Step 1: Write the proportion equation
   30,828.02 : 42,542.69 = 21,402.05 : x
2. Step 2: Convert to fraction form
   30,828.02/42,542.69 = 21,402.05/x
3. Step 3: Cross multiply
   30,828.02x = 42,542.69 × 21,402.05
4. Step 4: Simplify right side
   30,828.02x = 910,500,458.79
5. Step 5: Solve for x
   x = 910,500,458.79/30,828.02
6. Step 6: Final answer
   x = 29,534.84