Finding the Fourth Proportional to 1,390.03, 1,918.24 and 760.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.03 : 1,918.24 = 760.55 : x
2. Step 2: Convert to fraction form
   1,390.03/1,918.24 = 760.55/x
3. Step 3: Cross multiply
   1,390.03x = 1,918.24 × 760.55
4. Step 4: Simplify right side
   1,390.03x = 1,458,905.94
5. Step 5: Solve for x
   x = 1,458,905.94/1,390.03
6. Step 6: Final answer
   x = 1,049.55