Finding the Fourth Proportional to 1,245.40, 1,867.56 and 628.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.40 : 1,867.56 = 628.72 : x
2. Step 2: Convert to fraction form
   1,245.40/1,867.56 = 628.72/x
3. Step 3: Cross multiply
   1,245.40x = 1,867.56 × 628.72
4. Step 4: Simplify right side
   1,245.40x = 1,174,172.32
5. Step 5: Solve for x
   x = 1,174,172.32/1,245.40
6. Step 6: Final answer
   x = 942.81