Finding the Fourth Proportional to 1,166.77, 1,610.17 and 642.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,166.77 : 1,610.17 = 642.81 : x
2. Step 2: Convert to fraction form
   1,166.77/1,610.17 = 642.81/x
3. Step 3: Cross multiply
   1,166.77x = 1,610.17 × 642.81
4. Step 4: Simplify right side
   1,166.77x = 1,035,033.38
5. Step 5: Solve for x
   x = 1,035,033.38/1,166.77
6. Step 6: Final answer
   x = 887.09