Finding the Fourth Proportional to 1,397.52, 1,928.64 and 776.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.52 : 1,928.64 = 776.48 : x
2. Step 2: Convert to fraction form
   1,397.52/1,928.64 = 776.48/x
3. Step 3: Cross multiply
   1,397.52x = 1,928.64 × 776.48
4. Step 4: Simplify right side
   1,397.52x = 1,497,550.39
5. Step 5: Solve for x
   x = 1,497,550.39/1,397.52
6. Step 6: Final answer
   x = 1,071.58