Finding the Fourth Proportional to 1,166.06, 1,609.10 and 642.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,166.06 : 1,609.10 = 642.10 : x
2. Step 2: Convert to fraction form
   1,166.06/1,609.10 = 642.10/x
3. Step 3: Cross multiply
   1,166.06x = 1,609.10 × 642.10
4. Step 4: Simplify right side
   1,166.06x = 1,033,192.86
5. Step 5: Solve for x
   x = 1,033,192.86/1,166.06
6. Step 6: Final answer
   x = 886.05