Finding the Fourth Proportional to 1,369.48, 1,889.94 and 780.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.48 : 1,889.94 = 780.16 : x
2. Step 2: Convert to fraction form
   1,369.48/1,889.94 = 780.16/x
3. Step 3: Cross multiply
   1,369.48x = 1,889.94 × 780.16
4. Step 4: Simplify right side
   1,369.48x = 1,474,455.59
5. Step 5: Solve for x
   x = 1,474,455.59/1,369.48
6. Step 6: Final answer
   x = 1,076.65