Finding the Fourth Proportional to 1,112.67, 1,535.33 and 640.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.67 : 1,535.33 = 640.59 : x
2. Step 2: Convert to fraction form
   1,112.67/1,535.33 = 640.59/x
3. Step 3: Cross multiply
   1,112.67x = 1,535.33 × 640.59
4. Step 4: Simplify right side
   1,112.67x = 983,518.65
5. Step 5: Solve for x
   x = 983,518.65/1,112.67
6. Step 6: Final answer
   x = 883.93