Finding the Fourth Proportional to 1,378.99, 1,903.05 and 789.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.99 : 1,903.05 = 789.58 : x
2. Step 2: Convert to fraction form
   1,378.99/1,903.05 = 789.58/x
3. Step 3: Cross multiply
   1,378.99x = 1,903.05 × 789.58
4. Step 4: Simplify right side
   1,378.99x = 1,502,610.22
5. Step 5: Solve for x
   x = 1,502,610.22/1,378.99
6. Step 6: Final answer
   x = 1,089.65