Finding the Fourth Proportional to 1,397.77, 1,928.10 and 872.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.77 : 1,928.10 = 872.89 : x
2. Step 2: Convert to fraction form
   1,397.77/1,928.10 = 872.89/x
3. Step 3: Cross multiply
   1,397.77x = 1,928.10 × 872.89
4. Step 4: Simplify right side
   1,397.77x = 1,683,019.21
5. Step 5: Solve for x
   x = 1,683,019.21/1,397.77
6. Step 6: Final answer
   x = 1,204.07