Finding the Fourth Proportional to 1,015.69, 1,523.61 and 438.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.69 : 1,523.61 = 438.56 : x
2. Step 2: Convert to fraction form
   1,015.69/1,523.61 = 438.56/x
3. Step 3: Cross multiply
   1,015.69x = 1,523.61 × 438.56
4. Step 4: Simplify right side
   1,015.69x = 668,196.57
5. Step 5: Solve for x
   x = 668,196.57/1,015.69
6. Step 6: Final answer
   x = 657.88