Finding the Fourth Proportional to 9,991.32, 13,788.02 and 5,515.37

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991.32 : 13,788.02 = 5,515.37 : x
2. Step 2: Convert to fraction form
   9,991.32/13,788.02 = 5,515.37/x
3. Step 3: Cross multiply
   9,991.32x = 13,788.02 × 5,515.37
4. Step 4: Simplify right side
   9,991.32x = 76,046,031.87
5. Step 5: Solve for x
   x = 76,046,031.87/9,991.32
6. Step 6: Final answer
   x = 7,611.21