Finding the Fourth Proportional to 1,084.16, 1,496.34 and 642.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,084.16 : 1,496.34 = 642.30 : x
2. Step 2: Convert to fraction form
   1,084.16/1,496.34 = 642.30/x
3. Step 3: Cross multiply
   1,084.16x = 1,496.34 × 642.30
4. Step 4: Simplify right side
   1,084.16x = 961,099.18
5. Step 5: Solve for x
   x = 961,099.18/1,084.16
6. Step 6: Final answer
   x = 886.49