Finding the Fourth Proportional to 1,085.82, 1,497.75 and 643.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.82 : 1,497.75 = 643.41 : x
2. Step 2: Convert to fraction form
   1,085.82/1,497.75 = 643.41/x
3. Step 3: Cross multiply
   1,085.82x = 1,497.75 × 643.41
4. Step 4: Simplify right side
   1,085.82x = 963,667.33
5. Step 5: Solve for x
   x = 963,667.33/1,085.82
6. Step 6: Final answer
   x = 887.50