Finding the Fourth Proportional to 1,375.78, 1,898.61 and 778.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,375.78 : 1,898.61 = 778.22 : x
2. Step 2: Convert to fraction form
   1,375.78/1,898.61 = 778.22/x
3. Step 3: Cross multiply
   1,375.78x = 1,898.61 × 778.22
4. Step 4: Simplify right side
   1,375.78x = 1,477,532.38
5. Step 5: Solve for x
   x = 1,477,532.38/1,375.78
6. Step 6: Final answer
   x = 1,073.96