Finding the Fourth Proportional to 1,100.55, 1,648.67 and 638.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,100.55 : 1,648.67 = 638.04 : x
2. Step 2: Convert to fraction form
   1,100.55/1,648.67 = 638.04/x
3. Step 3: Cross multiply
   1,100.55x = 1,648.67 × 638.04
4. Step 4: Simplify right side
   1,100.55x = 1,051,914.22
5. Step 5: Solve for x
   x = 1,051,914.22/1,100.55
6. Step 6: Final answer
   x = 955.81