Finding the Fourth Proportional to 1,445.24, 1,994.42 and 815.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,445.24 : 1,994.42 = 815.57 : x
2. Step 2: Convert to fraction form
   1,445.24/1,994.42 = 815.57/x
3. Step 3: Cross multiply
   1,445.24x = 1,994.42 × 815.57
4. Step 4: Simplify right side
   1,445.24x = 1,626,588.67
5. Step 5: Solve for x
   x = 1,626,588.67/1,445.24
6. Step 6: Final answer
   x = 1,125.48