Finding the Fourth Proportional to 1,371.72, 1,892.99 and 782.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,371.72 : 1,892.99 = 782.31 : x
2. Step 2: Convert to fraction form
   1,371.72/1,892.99 = 782.31/x
3. Step 3: Cross multiply
   1,371.72x = 1,892.99 × 782.31
4. Step 4: Simplify right side
   1,371.72x = 1,480,905.01
5. Step 5: Solve for x
   x = 1,480,905.01/1,371.72
6. Step 6: Final answer
   x = 1,079.60