Finding the Fourth Proportional to 1,320.75, 1,978.59 and 671.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.75 : 1,978.59 = 671.94 : x
2. Step 2: Convert to fraction form
   1,320.75/1,978.59 = 671.94/x
3. Step 3: Cross multiply
   1,320.75x = 1,978.59 × 671.94
4. Step 4: Simplify right side
   1,320.75x = 1,329,493.76
5. Step 5: Solve for x
   x = 1,329,493.76/1,320.75
6. Step 6: Final answer
   x = 1,006.62