Finding the Fourth Proportional to 1,109.76, 1,530.78 and 717.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.76 : 1,530.78 = 717.06 : x
2. Step 2: Convert to fraction form
   1,109.76/1,530.78 = 717.06/x
3. Step 3: Cross multiply
   1,109.76x = 1,530.78 × 717.06
4. Step 4: Simplify right side
   1,109.76x = 1,097,661.11
5. Step 5: Solve for x
   x = 1,097,661.11/1,109.76
6. Step 6: Final answer
   x = 989.10