Finding the Fourth Proportional to 1,379.28, 1,903.40 and 749.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.28 : 1,903.40 = 749.80 : x
2. Step 2: Convert to fraction form
   1,379.28/1,903.40 = 749.80/x
3. Step 3: Cross multiply
   1,379.28x = 1,903.40 × 749.80
4. Step 4: Simplify right side
   1,379.28x = 1,427,169.32
5. Step 5: Solve for x
   x = 1,427,169.32/1,379.28
6. Step 6: Final answer
   x = 1,034.72