Finding the Fourth Proportional to 42,821.31, 64,138.18 and 21,725.11

Step by Step Solution

1. Step 1: Write the proportion equation
   42,821.31 : 64,138.18 = 21,725.11 : x
2. Step 2: Convert to fraction form
   42,821.31/64,138.18 = 21,725.11/x
3. Step 3: Cross multiply
   42,821.31x = 64,138.18 × 21,725.11
4. Step 4: Simplify right side
   42,821.31x = 1,393,409,082.29
5. Step 5: Solve for x
   x = 1,393,409,082.29/42,821.31
6. Step 6: Final answer
   x = 32,540.09