Finding the Fourth Proportional to 2,109.45, 3,164.18 and 648.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.45 : 3,164.18 = 648.60 : x
2. Step 2: Convert to fraction form
   2,109.45/3,164.18 = 648.60/x
3. Step 3: Cross multiply
   2,109.45x = 3,164.18 × 648.60
4. Step 4: Simplify right side
   2,109.45x = 2,052,283.91
5. Step 5: Solve for x
   x = 2,052,283.91/2,109.45
6. Step 6: Final answer
   x = 972.90