Finding the Fourth Proportional to 1,379.48, 1,903.64 and 789.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.48 : 1,903.64 = 789.98 : x
2. Step 2: Convert to fraction form
   1,379.48/1,903.64 = 789.98/x
3. Step 3: Cross multiply
   1,379.48x = 1,903.64 × 789.98
4. Step 4: Simplify right side
   1,379.48x = 1,503,824.06
5. Step 5: Solve for x
   x = 1,503,824.06/1,379.48
6. Step 6: Final answer
   x = 1,090.14