Finding the Fourth Proportional to 1,397.25, 1,928.25 and 776.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.25 : 1,928.25 = 776.25 : x
2. Step 2: Convert to fraction form
   1,397.25/1,928.25 = 776.25/x
3. Step 3: Cross multiply
   1,397.25x = 1,928.25 × 776.25
4. Step 4: Simplify right side
   1,397.25x = 1,496,804.06
5. Step 5: Solve for x
   x = 1,496,804.06/1,397.25
6. Step 6: Final answer
   x = 1,071.25