Finding the Fourth Proportional to 1,397.50, 1,928.55 and 776.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.50 : 1,928.55 = 776.62 : x
2. Step 2: Convert to fraction form
   1,397.50/1,928.55 = 776.62/x
3. Step 3: Cross multiply
   1,397.50x = 1,928.55 × 776.62
4. Step 4: Simplify right side
   1,397.50x = 1,497,750.50
5. Step 5: Solve for x
   x = 1,497,750.50/1,397.50
6. Step 6: Final answer
   x = 1,071.74