Finding the Fourth Proportional to 1,216.72, 1,679.23 and 880.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.72 : 1,679.23 = 880.75 : x
2. Step 2: Convert to fraction form
   1,216.72/1,679.23 = 880.75/x
3. Step 3: Cross multiply
   1,216.72x = 1,679.23 × 880.75
4. Step 4: Simplify right side
   1,216.72x = 1,478,980.30
5. Step 5: Solve for x
   x = 1,478,980.30/1,216.72
6. Step 6: Final answer
   x = 1,215.55