Finding the Fourth Proportional to 1,369.74, 1,890.24 and 780.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.74 : 1,890.24 = 780.27 : x
2. Step 2: Convert to fraction form
   1,369.74/1,890.24 = 780.27/x
3. Step 3: Cross multiply
   1,369.74x = 1,890.24 × 780.27
4. Step 4: Simplify right side
   1,369.74x = 1,474,897.56
5. Step 5: Solve for x
   x = 1,474,897.56/1,369.74
6. Step 6: Final answer
   x = 1,076.77