Finding the Fourth Proportional to 1,388,789.69, 1,916,485.72 and 776,953.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388,789.69 : 1,916,485.72 = 776,953.15 : x
2. Step 2: Convert to fraction form
   1,388,789.69/1,916,485.72 = 776,953.15/x
3. Step 3: Cross multiply
   1,388,789.69x = 1,916,485.72 × 776,953.15
4. Step 4: Simplify right side
   1,388,789.69x = 1,489,019,610,350.42
5. Step 5: Solve for x
   x = 1,489,019,610,350.42/1,388,789.69
6. Step 6: Final answer
   x = 1,072,170.70