Finding the Fourth Proportional to 9,619.90, 13,275.46 and 5,428.14

Step by Step Solution

1. Step 1: Write the proportion equation
   9,619.90 : 13,275.46 = 5,428.14 : x
2. Step 2: Convert to fraction form
   9,619.90/13,275.46 = 5,428.14/x
3. Step 3: Cross multiply
   9,619.90x = 13,275.46 × 5,428.14
4. Step 4: Simplify right side
   9,619.90x = 72,061,055.44
5. Step 5: Solve for x
   x = 72,061,055.44/9,619.90
6. Step 6: Final answer
   x = 7,490.83