Finding the Fourth Proportional to 1,321.72, 1,824.78 and 880

Step by Step Solution

1. Step 1: Write the proportion equation
   1,321.72 : 1,824.78 = 880 : x
2. Step 2: Convert to fraction form
   1,321.72/1,824.78 = 880/x
3. Step 3: Cross multiply
   1,321.72x = 1,824.78 × 880
4. Step 4: Simplify right side
   1,321.72x = 1,605,806.40
5. Step 5: Solve for x
   x = 1,605,806.40/1,321.72
6. Step 6: Final answer
   x = 1,214.94