Finding the Fourth Proportional to 1,338.64, 1,846.72 and 778.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,338.64 : 1,846.72 = 778.96 : x
2. Step 2: Convert to fraction form
   1,338.64/1,846.72 = 778.96/x
3. Step 3: Cross multiply
   1,338.64x = 1,846.72 × 778.96
4. Step 4: Simplify right side
   1,338.64x = 1,438,514.45
5. Step 5: Solve for x
   x = 1,438,514.45/1,338.64
6. Step 6: Final answer
   x = 1,074.61