Finding the Fourth Proportional to 1,665.21, 2,498.09 and 510.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.21 : 2,498.09 = 510.69 : x
2. Step 2: Convert to fraction form
   1,665.21/2,498.09 = 510.69/x
3. Step 3: Cross multiply
   1,665.21x = 2,498.09 × 510.69
4. Step 4: Simplify right side
   1,665.21x = 1,275,749.58
5. Step 5: Solve for x
   x = 1,275,749.58/1,665.21
6. Step 6: Final answer
   x = 766.12