Finding the Fourth Proportional to 1,511.72, 2,086.20 and 922.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,511.72 : 2,086.20 = 922.31 : x
2. Step 2: Convert to fraction form
   1,511.72/2,086.20 = 922.31/x
3. Step 3: Cross multiply
   1,511.72x = 2,086.20 × 922.31
4. Step 4: Simplify right side
   1,511.72x = 1,924,118.51
5. Step 5: Solve for x
   x = 1,924,118.51/1,511.72
6. Step 6: Final answer
   x = 1,272.80