Finding the Fourth Proportional to 1,016.28, 1,523.61 and 438.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.28 : 1,523.61 = 438.75 : x
2. Step 2: Convert to fraction form
   1,016.28/1,523.61 = 438.75/x
3. Step 3: Cross multiply
   1,016.28x = 1,523.61 × 438.75
4. Step 4: Simplify right side
   1,016.28x = 668,483.89
5. Step 5: Solve for x
   x = 668,483.89/1,016.28
6. Step 6: Final answer
   x = 657.78