Finding the Fourth Proportional to 21,011.42, 31,517.68 and 5,429

Step by Step Solution

1. Step 1: Write the proportion equation
   21,011.42 : 31,517.68 = 5,429 : x
2. Step 2: Convert to fraction form
   21,011.42/31,517.68 = 5,429/x
3. Step 3: Cross multiply
   21,011.42x = 31,517.68 × 5,429
4. Step 4: Simplify right side
   21,011.42x = 171,109,484.72
5. Step 5: Solve for x
   x = 171,109,484.72/21,011.42
6. Step 6: Final answer
   x = 8,143.64