Finding the Fourth Proportional to 1,215.82, 1,822.17 and 521.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.82 : 1,822.17 = 521.68 : x
2. Step 2: Convert to fraction form
   1,215.82/1,822.17 = 521.68/x
3. Step 3: Cross multiply
   1,215.82x = 1,822.17 × 521.68
4. Step 4: Simplify right side
   1,215.82x = 950,589.65
5. Step 5: Solve for x
   x = 950,589.65/1,215.82
6. Step 6: Final answer
   x = 781.85