Finding the Fourth Proportional to 1,112.24, 1,534.83 and 640.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.24 : 1,534.83 = 640.15 : x
2. Step 2: Convert to fraction form
   1,112.24/1,534.83 = 640.15/x
3. Step 3: Cross multiply
   1,112.24x = 1,534.83 × 640.15
4. Step 4: Simplify right side
   1,112.24x = 982,526.07
5. Step 5: Solve for x
   x = 982,526.07/1,112.24
6. Step 6: Final answer
   x = 883.38