Finding the Fourth Proportional to 1,039.76, 1,434.56 and 666.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.76 : 1,434.56 = 666.08 : x
2. Step 2: Convert to fraction form
   1,039.76/1,434.56 = 666.08/x
3. Step 3: Cross multiply
   1,039.76x = 1,434.56 × 666.08
4. Step 4: Simplify right side
   1,039.76x = 955,531.72
5. Step 5: Solve for x
   x = 955,531.72/1,039.76
6. Step 6: Final answer
   x = 918.99