Finding the Fourth Proportional to 2,665.72, 3,998.61 and 1,021.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.72 : 3,998.61 = 1,021.88 : x
2. Step 2: Convert to fraction form
   2,665.72/3,998.61 = 1,021.88/x
3. Step 3: Cross multiply
   2,665.72x = 3,998.61 × 1,021.88
4. Step 4: Simplify right side
   2,665.72x = 4,086,075.76
5. Step 5: Solve for x
   x = 4,086,075.76/2,665.72
6. Step 6: Final answer
   x = 1,532.82