Finding the Fourth Proportional to 1,397.59, 1,928.94 and 830.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.59 : 1,928.94 = 830.55 : x
2. Step 2: Convert to fraction form
   1,397.59/1,928.94 = 830.55/x
3. Step 3: Cross multiply
   1,397.59x = 1,928.94 × 830.55
4. Step 4: Simplify right side
   1,397.59x = 1,602,084.48
5. Step 5: Solve for x
   x = 1,602,084.48/1,397.59
6. Step 6: Final answer
   x = 1,146.32