Finding the Fourth Proportional to 2,548.34, 3,820.08 and 815.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,548.34 : 3,820.08 = 815.78 : x
2. Step 2: Convert to fraction form
   2,548.34/3,820.08 = 815.78/x
3. Step 3: Cross multiply
   2,548.34x = 3,820.08 × 815.78
4. Step 4: Simplify right side
   2,548.34x = 3,116,344.86
5. Step 5: Solve for x
   x = 3,116,344.86/2,548.34
6. Step 6: Final answer
   x = 1,222.89