Finding the Fourth Proportional to 1,172.57, 1,618.15 and 641.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.57 : 1,618.15 = 641.46 : x
2. Step 2: Convert to fraction form
   1,172.57/1,618.15 = 641.46/x
3. Step 3: Cross multiply
   1,172.57x = 1,618.15 × 641.46
4. Step 4: Simplify right side
   1,172.57x = 1,037,978.50
5. Step 5: Solve for x
   x = 1,037,978.50/1,172.57
6. Step 6: Final answer
   x = 885.22