Finding the Fourth Proportional to 1,215.10, 1,676.55 and 691.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.10 : 1,676.55 = 691.42 : x
2. Step 2: Convert to fraction form
   1,215.10/1,676.55 = 691.42/x
3. Step 3: Cross multiply
   1,215.10x = 1,676.55 × 691.42
4. Step 4: Simplify right side
   1,215.10x = 1,159,200.20
5. Step 5: Solve for x
   x = 1,159,200.20/1,215.10
6. Step 6: Final answer
   x = 954.00