Finding the Fourth Proportional to 1,238.78, 1,709.69 and 797.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.78 : 1,709.69 = 797.96 : x
2. Step 2: Convert to fraction form
   1,238.78/1,709.69 = 797.96/x
3. Step 3: Cross multiply
   1,238.78x = 1,709.69 × 797.96
4. Step 4: Simplify right side
   1,238.78x = 1,364,251.69
5. Step 5: Solve for x
   x = 1,364,251.69/1,238.78
6. Step 6: Final answer
   x = 1,101.29