Finding the Fourth Proportional to 1,081.38, 1,620.45 and 648.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.38 : 1,620.45 = 648.03 : x
2. Step 2: Convert to fraction form
   1,081.38/1,620.45 = 648.03/x
3. Step 3: Cross multiply
   1,081.38x = 1,620.45 × 648.03
4. Step 4: Simplify right side
   1,081.38x = 1,050,100.21
5. Step 5: Solve for x
   x = 1,050,100.21/1,081.38
6. Step 6: Final answer
   x = 971.07