Finding the Fourth Proportional to 21,011.63, 31,518.05 and 5,429.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,011.63 : 31,518.05 = 5,429.25 : x
2. Step 2: Convert to fraction form
   21,011.63/31,518.05 = 5,429.25/x
3. Step 3: Cross multiply
   21,011.63x = 31,518.05 × 5,429.25
4. Step 4: Simplify right side
   21,011.63x = 171,119,345.82
5. Step 5: Solve for x
   x = 171,119,345.82/21,011.63
6. Step 6: Final answer
   x = 8,144.03