Finding the Fourth Proportional to 1,399.72, 1,931.63 and 770.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.72 : 1,931.63 = 770.29 : x
2. Step 2: Convert to fraction form
   1,399.72/1,931.63 = 770.29/x
3. Step 3: Cross multiply
   1,399.72x = 1,931.63 × 770.29
4. Step 4: Simplify right side
   1,399.72x = 1,487,906.59
5. Step 5: Solve for x
   x = 1,487,906.59/1,399.72
6. Step 6: Final answer
   x = 1,063.00