Finding the Fourth Proportional to 1,369.53, 1,889.96 and 780.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.53 : 1,889.96 = 780.09 : x
2. Step 2: Convert to fraction form
   1,369.53/1,889.96 = 780.09/x
3. Step 3: Cross multiply
   1,369.53x = 1,889.96 × 780.09
4. Step 4: Simplify right side
   1,369.53x = 1,474,335.00
5. Step 5: Solve for x
   x = 1,474,335.00/1,369.53
6. Step 6: Final answer
   x = 1,076.53