Finding the Fourth Proportional to 1,167.38, 1,610.98 and 643.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.38 : 1,610.98 = 643.42 : x
2. Step 2: Convert to fraction form
   1,167.38/1,610.98 = 643.42/x
3. Step 3: Cross multiply
   1,167.38x = 1,610.98 × 643.42
4. Step 4: Simplify right side
   1,167.38x = 1,036,531.12
5. Step 5: Solve for x
   x = 1,036,531.12/1,167.38
6. Step 6: Final answer
   x = 887.92