Finding the Fourth Proportional to 1,986.56, 2,979.72 and 688.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,986.56 : 2,979.72 = 688.04 : x
2. Step 2: Convert to fraction form
   1,986.56/2,979.72 = 688.04/x
3. Step 3: Cross multiply
   1,986.56x = 2,979.72 × 688.04
4. Step 4: Simplify right side
   1,986.56x = 2,050,166.55
5. Step 5: Solve for x
   x = 2,050,166.55/1,986.56
6. Step 6: Final answer
   x = 1,032.02