Finding the Fourth Proportional to 1,679.36, 2,517.31 and 1,215.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,679.36 : 2,517.31 = 1,215.99 : x
2. Step 2: Convert to fraction form
   1,679.36/2,517.31 = 1,215.99/x
3. Step 3: Cross multiply
   1,679.36x = 2,517.31 × 1,215.99
4. Step 4: Simplify right side
   1,679.36x = 3,061,023.79
5. Step 5: Solve for x
   x = 3,061,023.79/1,679.36
6. Step 6: Final answer
   x = 1,822.73