Finding the Fourth Proportional to 2,615.34, 3,922.28 and 859.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.34 : 3,922.28 = 859.72 : x
2. Step 2: Convert to fraction form
   2,615.34/3,922.28 = 859.72/x
3. Step 3: Cross multiply
   2,615.34x = 3,922.28 × 859.72
4. Step 4: Simplify right side
   2,615.34x = 3,372,062.56
5. Step 5: Solve for x
   x = 3,372,062.56/2,615.34
6. Step 6: Final answer
   x = 1,289.34