Finding the Fourth Proportional to 1,165.67, 1,608.66 and 641.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.67 : 1,608.66 = 641.72 : x
2. Step 2: Convert to fraction form
   1,165.67/1,608.66 = 641.72/x
3. Step 3: Cross multiply
   1,165.67x = 1,608.66 × 641.72
4. Step 4: Simplify right side
   1,165.67x = 1,032,309.30
5. Step 5: Solve for x
   x = 1,032,309.30/1,165.67
6. Step 6: Final answer
   x = 885.59