Finding the Fourth Proportional to 9,620.56, 13,274.85 and 5,428

Step by Step Solution

1. Step 1: Write the proportion equation
   9,620.56 : 13,274.85 = 5,428 : x
2. Step 2: Convert to fraction form
   9,620.56/13,274.85 = 5,428/x
3. Step 3: Cross multiply
   9,620.56x = 13,274.85 × 5,428
4. Step 4: Simplify right side
   9,620.56x = 72,055,885.80
5. Step 5: Solve for x
   x = 72,055,885.80/9,620.56
6. Step 6: Final answer
   x = 7,489.78