Finding the Fourth Proportional to 1,215.57, 1,676.74 and 773.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.57 : 1,676.74 = 773.10 : x
2. Step 2: Convert to fraction form
   1,215.57/1,676.74 = 773.10/x
3. Step 3: Cross multiply
   1,215.57x = 1,676.74 × 773.10
4. Step 4: Simplify right side
   1,215.57x = 1,296,287.69
5. Step 5: Solve for x
   x = 1,296,287.69/1,215.57
6. Step 6: Final answer
   x = 1,066.40