Finding the Fourth Proportional to 1,314.88, 1,970.88 and 664.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,314.88 : 1,970.88 = 664.72 : x
2. Step 2: Convert to fraction form
   1,314.88/1,970.88 = 664.72/x
3. Step 3: Cross multiply
   1,314.88x = 1,970.88 × 664.72
4. Step 4: Simplify right side
   1,314.88x = 1,310,083.35
5. Step 5: Solve for x
   x = 1,310,083.35/1,314.88
6. Step 6: Final answer
   x = 996.35