Finding the Fourth Proportional to 1,114.55, 1,538.02 and 642.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,114.55 : 1,538.02 = 642.41 : x
2. Step 2: Convert to fraction form
   1,114.55/1,538.02 = 642.41/x
3. Step 3: Cross multiply
   1,114.55x = 1,538.02 × 642.41
4. Step 4: Simplify right side
   1,114.55x = 988,039.43
5. Step 5: Solve for x
   x = 988,039.43/1,114.55
6. Step 6: Final answer
   x = 886.49