Finding the Fourth Proportional to 1,112.45, 1,535.25 and 640.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.45 : 1,535.25 = 640.37 : x
2. Step 2: Convert to fraction form
   1,112.45/1,535.25 = 640.37/x
3. Step 3: Cross multiply
   1,112.45x = 1,535.25 × 640.37
4. Step 4: Simplify right side
   1,112.45x = 983,120.37
5. Step 5: Solve for x
   x = 983,120.37/1,112.45
6. Step 6: Final answer
   x = 883.75