Finding the Fourth Proportional to 1,379.30, 1,902.78 and 1,005.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.30 : 1,902.78 = 1,005.48 : x
2. Step 2: Convert to fraction form
   1,379.30/1,902.78 = 1,005.48/x
3. Step 3: Cross multiply
   1,379.30x = 1,902.78 × 1,005.48
4. Step 4: Simplify right side
   1,379.30x = 1,913,207.23
5. Step 5: Solve for x
   x = 1,913,207.23/1,379.30
6. Step 6: Final answer
   x = 1,387.09