Finding the Fourth Proportional to 1,008.72, 1,510.20 and 854.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.72 : 1,510.20 = 854.64 : x
2. Step 2: Convert to fraction form
   1,008.72/1,510.20 = 854.64/x
3. Step 3: Cross multiply
   1,008.72x = 1,510.20 × 854.64
4. Step 4: Simplify right side
   1,008.72x = 1,290,677.33
5. Step 5: Solve for x
   x = 1,290,677.33/1,008.72
6. Step 6: Final answer
   x = 1,279.52