Finding the Fourth Proportional to 2,109.08, 3,162.78 and 648.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.08 : 3,162.78 = 648.20 : x
2. Step 2: Convert to fraction form
   2,109.08/3,162.78 = 648.20/x
3. Step 3: Cross multiply
   2,109.08x = 3,162.78 × 648.20
4. Step 4: Simplify right side
   2,109.08x = 2,050,114.00
5. Step 5: Solve for x
   x = 2,050,114.00/2,109.08
6. Step 6: Final answer
   x = 972.04