Finding the Fourth Proportional to 1,397.20, 1,928.25 and 900.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.20 : 1,928.25 = 900.87 : x
2. Step 2: Convert to fraction form
   1,397.20/1,928.25 = 900.87/x
3. Step 3: Cross multiply
   1,397.20x = 1,928.25 × 900.87
4. Step 4: Simplify right side
   1,397.20x = 1,737,100.33
5. Step 5: Solve for x
   x = 1,737,100.33/1,397.20
6. Step 6: Final answer
   x = 1,243.27