Finding the Fourth Proportional to 1,080.99, 1,621.89 and 648.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.99 : 1,621.89 = 648.45 : x
2. Step 2: Convert to fraction form
   1,080.99/1,621.89 = 648.45/x
3. Step 3: Cross multiply
   1,080.99x = 1,621.89 × 648.45
4. Step 4: Simplify right side
   1,080.99x = 1,051,714.57
5. Step 5: Solve for x
   x = 1,051,714.57/1,080.99
6. Step 6: Final answer
   x = 972.92