Finding the Fourth Proportional to 1,167.59, 1,611.23 and 643.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,167.59 : 1,611.23 = 643.61 : x
2. Step 2: Convert to fraction form
   1,167.59/1,611.23 = 643.61/x
3. Step 3: Cross multiply
   1,167.59x = 1,611.23 × 643.61
4. Step 4: Simplify right side
   1,167.59x = 1,036,992.47
5. Step 5: Solve for x
   x = 1,036,992.47/1,167.59
6. Step 6: Final answer
   x = 888.15