Finding the Fourth Proportional to 1,397.31, 1,928.36 and 776.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.31 : 1,928.36 = 776.31 : x
2. Step 2: Convert to fraction form
   1,397.31/1,928.36 = 776.31/x
3. Step 3: Cross multiply
   1,397.31x = 1,928.36 × 776.31
4. Step 4: Simplify right side
   1,397.31x = 1,497,001.27
5. Step 5: Solve for x
   x = 1,497,001.27/1,397.31
6. Step 6: Final answer
   x = 1,071.35