Finding the Fourth Proportional to 1,393.89, 1,923.18 and 897.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.89 : 1,923.18 = 897.21 : x
2. Step 2: Convert to fraction form
   1,393.89/1,923.18 = 897.21/x
3. Step 3: Cross multiply
   1,393.89x = 1,923.18 × 897.21
4. Step 4: Simplify right side
   1,393.89x = 1,725,496.33
5. Step 5: Solve for x
   x = 1,725,496.33/1,393.89
6. Step 6: Final answer
   x = 1,237.90