Finding the Fourth Proportional to 9,920.54, 13,690.59 and 5,613.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.54 : 13,690.59 = 5,613.28 : x
2. Step 2: Convert to fraction form
   9,920.54/13,690.59 = 5,613.28/x
3. Step 3: Cross multiply
   9,920.54x = 13,690.59 × 5,613.28
4. Step 4: Simplify right side
   9,920.54x = 76,849,080.81
5. Step 5: Solve for x
   x = 76,849,080.81/9,920.54
6. Step 6: Final answer
   x = 7,746.47