Finding the Fourth Proportional to 1,166.03, 1,609.07 and 642.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,166.03 : 1,609.07 = 642.05 : x
2. Step 2: Convert to fraction form
   1,166.03/1,609.07 = 642.05/x
3. Step 3: Cross multiply
   1,166.03x = 1,609.07 × 642.05
4. Step 4: Simplify right side
   1,166.03x = 1,033,100.18
5. Step 5: Solve for x
   x = 1,033,100.18/1,166.03
6. Step 6: Final answer
   x = 886.00