Finding the Fourth Proportional to 1,112.55, 1,664.79 and 672.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.55 : 1,664.79 = 672.18 : x
2. Step 2: Convert to fraction form
   1,112.55/1,664.79 = 672.18/x
3. Step 3: Cross multiply
   1,112.55x = 1,664.79 × 672.18
4. Step 4: Simplify right side
   1,112.55x = 1,119,038.54
5. Step 5: Solve for x
   x = 1,119,038.54/1,112.55
6. Step 6: Final answer
   x = 1,005.83