Finding the Fourth Proportional to 1,109.56, 1,665.58 and 647.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.56 : 1,665.58 = 647.88 : x
2. Step 2: Convert to fraction form
   1,109.56/1,665.58 = 647.88/x
3. Step 3: Cross multiply
   1,109.56x = 1,665.58 × 647.88
4. Step 4: Simplify right side
   1,109.56x = 1,079,095.97
5. Step 5: Solve for x
   x = 1,079,095.97/1,109.56
6. Step 6: Final answer
   x = 972.54