Finding the Fourth Proportional to 1,380.66, 1,904.64 and 961.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.66 : 1,904.64 = 961.98 : x
2. Step 2: Convert to fraction form
   1,380.66/1,904.64 = 961.98/x
3. Step 3: Cross multiply
   1,380.66x = 1,904.64 × 961.98
4. Step 4: Simplify right side
   1,380.66x = 1,832,225.59
5. Step 5: Solve for x
   x = 1,832,225.59/1,380.66
6. Step 6: Final answer
   x = 1,327.07