Finding the Fourth Proportional to 1,218.31, 1,681.36 and 714.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,218.31 : 1,681.36 = 714.15 : x
2. Step 2: Convert to fraction form
   1,218.31/1,681.36 = 714.15/x
3. Step 3: Cross multiply
   1,218.31x = 1,681.36 × 714.15
4. Step 4: Simplify right side
   1,218.31x = 1,200,741.46
5. Step 5: Solve for x
   x = 1,200,741.46/1,218.31
6. Step 6: Final answer
   x = 985.58