Finding the Fourth Proportional to 1,969.72, 2,955.78 and 815.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,969.72 : 2,955.78 = 815.32 : x
2. Step 2: Convert to fraction form
   1,969.72/2,955.78 = 815.32/x
3. Step 3: Cross multiply
   1,969.72x = 2,955.78 × 815.32
4. Step 4: Simplify right side
   1,969.72x = 2,409,906.55
5. Step 5: Solve for x
   x = 2,409,906.55/1,969.72
6. Step 6: Final answer
   x = 1,223.48