Finding the Fourth Proportional to 9,407.98, 12,980.94 and 5,428.25

Step by Step Solution

1. Step 1: Write the proportion equation
   9,407.98 : 12,980.94 = 5,428.25 : x
2. Step 2: Convert to fraction form
   9,407.98/12,980.94 = 5,428.25/x
3. Step 3: Cross multiply
   9,407.98x = 12,980.94 × 5,428.25
4. Step 4: Simplify right side
   9,407.98x = 70,463,781.51
5. Step 5: Solve for x
   x = 70,463,781.51/9,407.98
6. Step 6: Final answer
   x = 7,489.79