Finding the Fourth Proportional to 1,213.57, 1,674.62 and 689.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.57 : 1,674.62 = 689.50 : x
2. Step 2: Convert to fraction form
   1,213.57/1,674.62 = 689.50/x
3. Step 3: Cross multiply
   1,213.57x = 1,674.62 × 689.50
4. Step 4: Simplify right side
   1,213.57x = 1,154,647.04
5. Step 5: Solve for x
   x = 1,154,647.04/1,213.57
6. Step 6: Final answer
   x = 951.45