Finding the Fourth Proportional to 1,379.61, 1,903.56 and 1,006.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.61 : 1,903.56 = 1,006.79 : x
2. Step 2: Convert to fraction form
   1,379.61/1,903.56 = 1,006.79/x
3. Step 3: Cross multiply
   1,379.61x = 1,903.56 × 1,006.79
4. Step 4: Simplify right side
   1,379.61x = 1,916,485.17
5. Step 5: Solve for x
   x = 1,916,485.17/1,379.61
6. Step 6: Final answer
   x = 1,389.15