Finding the Fourth Proportional to 1,031.72, 1,424.24 and 718.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,031.72 : 1,424.24 = 718.06 : x
2. Step 2: Convert to fraction form
   1,031.72/1,424.24 = 718.06/x
3. Step 3: Cross multiply
   1,031.72x = 1,424.24 × 718.06
4. Step 4: Simplify right side
   1,031.72x = 1,022,689.77
5. Step 5: Solve for x
   x = 1,022,689.77/1,031.72
6. Step 6: Final answer
   x = 991.25