Finding the Fourth Proportional to 21,011.55, 31,518.21 and 9,777.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,011.55 : 31,518.21 = 9,777.42 : x
2. Step 2: Convert to fraction form
   21,011.55/31,518.21 = 9,777.42/x
3. Step 3: Cross multiply
   21,011.55x = 31,518.21 × 9,777.42
4. Step 4: Simplify right side
   21,011.55x = 308,166,776.82
5. Step 5: Solve for x
   x = 308,166,776.82/21,011.55
6. Step 6: Final answer
   x = 14,666.54