Finding the Fourth Proportional to 1,379.52, 1,906.20 and 961.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.52 : 1,906.20 = 961.56 : x
2. Step 2: Convert to fraction form
   1,379.52/1,906.20 = 961.56/x
3. Step 3: Cross multiply
   1,379.52x = 1,906.20 × 961.56
4. Step 4: Simplify right side
   1,379.52x = 1,832,925.67
5. Step 5: Solve for x
   x = 1,832,925.67/1,379.52
6. Step 6: Final answer
   x = 1,328.67