Finding the Fourth Proportional to 1,164.58, 1,607.15 and 640.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,164.58 : 1,607.15 = 640.61 : x
2. Step 2: Convert to fraction form
   1,164.58/1,607.15 = 640.61/x
3. Step 3: Cross multiply
   1,164.58x = 1,607.15 × 640.61
4. Step 4: Simplify right side
   1,164.58x = 1,029,561.98
5. Step 5: Solve for x
   x = 1,029,561.98/1,164.58
6. Step 6: Final answer
   x = 884.06