Finding the Fourth Proportional to 1,985.34, 2,978.34 and 686.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.34 : 2,978.34 = 686.50 : x
2. Step 2: Convert to fraction form
   1,985.34/2,978.34 = 686.50/x
3. Step 3: Cross multiply
   1,985.34x = 2,978.34 × 686.50
4. Step 4: Simplify right side
   1,985.34x = 2,044,630.41
5. Step 5: Solve for x
   x = 2,044,630.41/1,985.34
6. Step 6: Final answer
   x = 1,029.87