Finding the Fourth Proportional to 1,538.70, 2,308.18 and 443.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.70 : 2,308.18 = 443.10 : x
2. Step 2: Convert to fraction form
   1,538.70/2,308.18 = 443.10/x
3. Step 3: Cross multiply
   1,538.70x = 2,308.18 × 443.10
4. Step 4: Simplify right side
   1,538.70x = 1,022,754.56
5. Step 5: Solve for x
   x = 1,022,754.56/1,538.70
6. Step 6: Final answer
   x = 664.69