Finding the Fourth Proportional to 1,985.72, 2,978.18 and 669.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.72 : 2,978.18 = 669.32 : x
2. Step 2: Convert to fraction form
   1,985.72/2,978.18 = 669.32/x
3. Step 3: Cross multiply
   1,985.72x = 2,978.18 × 669.32
4. Step 4: Simplify right side
   1,985.72x = 1,993,355.44
5. Step 5: Solve for x
   x = 1,993,355.44/1,985.72
6. Step 6: Final answer
   x = 1,003.85