Finding the Fourth Proportional to 1,398.87, 1,931.24 and 902.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.87 : 1,931.24 = 902.24 : x
2. Step 2: Convert to fraction form
   1,398.87/1,931.24 = 902.24/x
3. Step 3: Cross multiply
   1,398.87x = 1,931.24 × 902.24
4. Step 4: Simplify right side
   1,398.87x = 1,742,441.82
5. Step 5: Solve for x
   x = 1,742,441.82/1,398.87
6. Step 6: Final answer
   x = 1,245.61