Finding the Fourth Proportional to 1,085.83, 1,497.96 and 643.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.83 : 1,497.96 = 643.48 : x
2. Step 2: Convert to fraction form
   1,085.83/1,497.96 = 643.48/x
3. Step 3: Cross multiply
   1,085.83x = 1,497.96 × 643.48
4. Step 4: Simplify right side
   1,085.83x = 963,907.30
5. Step 5: Solve for x
   x = 963,907.30/1,085.83
6. Step 6: Final answer
   x = 887.71