Finding the Fourth Proportional to 1,165.84, 1,608.87 and 641.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.84 : 1,608.87 = 641.89 : x
2. Step 2: Convert to fraction form
   1,165.84/1,608.87 = 641.89/x
3. Step 3: Cross multiply
   1,165.84x = 1,608.87 × 641.89
4. Step 4: Simplify right side
   1,165.84x = 1,032,717.56
5. Step 5: Solve for x
   x = 1,032,717.56/1,165.84
6. Step 6: Final answer
   x = 885.81