Finding the Fourth Proportional to 1,166.00, 1,609.10 and 642.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,166.00 : 1,609.10 = 642.05 : x
2. Step 2: Convert to fraction form
   1,166.00/1,609.10 = 642.05/x
3. Step 3: Cross multiply
   1,166.00x = 1,609.10 × 642.05
4. Step 4: Simplify right side
   1,166.00x = 1,033,111.40
5. Step 5: Solve for x
   x = 1,033,111.40/1,166.00
6. Step 6: Final answer
   x = 886.03