Finding the Fourth Proportional to 1,085.06, 1,496.72 and 642.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.06 : 1,496.72 = 642.67 : x
2. Step 2: Convert to fraction form
   1,085.06/1,496.72 = 642.67/x
3. Step 3: Cross multiply
   1,085.06x = 1,496.72 × 642.67
4. Step 4: Simplify right side
   1,085.06x = 961,894.91
5. Step 5: Solve for x
   x = 961,894.91/1,085.06
6. Step 6: Final answer
   x = 886.49