Finding the Fourth Proportional to 9,920.88, 13,690.53 and 5,613.57

Step by Step Solution

1. Step 1: Write the proportion equation
   9,920.88 : 13,690.53 = 5,613.57 : x
2. Step 2: Convert to fraction form
   9,920.88/13,690.53 = 5,613.57/x
3. Step 3: Cross multiply
   9,920.88x = 13,690.53 × 5,613.57
4. Step 4: Simplify right side
   9,920.88x = 76,852,748.49
5. Step 5: Solve for x
   x = 76,852,748.49/9,920.88
6. Step 6: Final answer
   x = 7,746.57