Finding the Fourth Proportional to 1,165.59, 1,608.53 and 641.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.59 : 1,608.53 = 641.63 : x
2. Step 2: Convert to fraction form
   1,165.59/1,608.53 = 641.63/x
3. Step 3: Cross multiply
   1,165.59x = 1,608.53 × 641.63
4. Step 4: Simplify right side
   1,165.59x = 1,032,069.85
5. Step 5: Solve for x
   x = 1,032,069.85/1,165.59
6. Step 6: Final answer
   x = 885.45