Finding the Fourth Proportional to 1,071.79, 1,477.31 and 717.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.79 : 1,477.31 = 717.59 : x
2. Step 2: Convert to fraction form
   1,071.79/1,477.31 = 717.59/x
3. Step 3: Cross multiply
   1,071.79x = 1,477.31 × 717.59
4. Step 4: Simplify right side
   1,071.79x = 1,060,102.88
5. Step 5: Solve for x
   x = 1,060,102.88/1,071.79
6. Step 6: Final answer
   x = 989.10