Finding the Fourth Proportional to 1,166.96, 1,610.42 and 643.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,166.96 : 1,610.42 = 643.03 : x
2. Step 2: Convert to fraction form
   1,166.96/1,610.42 = 643.03/x
3. Step 3: Cross multiply
   1,166.96x = 1,610.42 × 643.03
4. Step 4: Simplify right side
   1,166.96x = 1,035,548.37
5. Step 5: Solve for x
   x = 1,035,548.37/1,166.96
6. Step 6: Final answer
   x = 887.39