Finding the Fourth Proportional to 1,370.78, 1,891.72 and 749.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,370.78 : 1,891.72 = 749.78 : x
2. Step 2: Convert to fraction form
   1,370.78/1,891.72 = 749.78/x
3. Step 3: Cross multiply
   1,370.78x = 1,891.72 × 749.78
4. Step 4: Simplify right side
   1,370.78x = 1,418,379.00
5. Step 5: Solve for x
   x = 1,418,379.00/1,370.78
6. Step 6: Final answer
   x = 1,034.72