Finding the Fourth Proportional to 1,398.57, 1,930.14 and 874.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.57 : 1,930.14 = 874.50 : x
2. Step 2: Convert to fraction form
   1,398.57/1,930.14 = 874.50/x
3. Step 3: Cross multiply
   1,398.57x = 1,930.14 × 874.50
4. Step 4: Simplify right side
   1,398.57x = 1,687,907.43
5. Step 5: Solve for x
   x = 1,687,907.43/1,398.57
6. Step 6: Final answer
   x = 1,206.88