Finding the Fourth Proportional to 1,028.69, 1,418.15 and 870.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,028.69 : 1,418.15 = 870.69 : x
2. Step 2: Convert to fraction form
   1,028.69/1,418.15 = 870.69/x
3. Step 3: Cross multiply
   1,028.69x = 1,418.15 × 870.69
4. Step 4: Simplify right side
   1,028.69x = 1,234,771.20
5. Step 5: Solve for x
   x = 1,234,771.20/1,028.69
6. Step 6: Final answer
   x = 1,200.34