Finding the Fourth Proportional to 1,278.72, 1,928.70 and 1,126.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,278.72 : 1,928.70 = 1,126.56 : x
2. Step 2: Convert to fraction form
   1,278.72/1,928.70 = 1,126.56/x
3. Step 3: Cross multiply
   1,278.72x = 1,928.70 × 1,126.56
4. Step 4: Simplify right side
   1,278.72x = 2,172,796.27
5. Step 5: Solve for x
   x = 2,172,796.27/1,278.72
6. Step 6: Final answer
   x = 1,699.20