Finding the Fourth Proportional to 1,445.31, 1,994.40 and 815.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,445.31 : 1,994.40 = 815.81 : x
2. Step 2: Convert to fraction form
   1,445.31/1,994.40 = 815.81/x
3. Step 3: Cross multiply
   1,445.31x = 1,994.40 × 815.81
4. Step 4: Simplify right side
   1,445.31x = 1,627,041.49
5. Step 5: Solve for x
   x = 1,627,041.49/1,445.31
6. Step 6: Final answer
   x = 1,125.74