Finding the Fourth Proportional to 1,212.56, 1,672.54 and 714.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,212.56 : 1,672.54 = 714.78 : x
2. Step 2: Convert to fraction form
   1,212.56/1,672.54 = 714.78/x
3. Step 3: Cross multiply
   1,212.56x = 1,672.54 × 714.78
4. Step 4: Simplify right side
   1,212.56x = 1,195,498.14
5. Step 5: Solve for x
   x = 1,195,498.14/1,212.56
6. Step 6: Final answer
   x = 985.93