Finding the Fourth Proportional to 9,991.83, 13,788.44 and 5,515.25

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991.83 : 13,788.44 = 5,515.25 : x
2. Step 2: Convert to fraction form
   9,991.83/13,788.44 = 5,515.25/x
3. Step 3: Cross multiply
   9,991.83x = 13,788.44 × 5,515.25
4. Step 4: Simplify right side
   9,991.83x = 76,046,693.71
5. Step 5: Solve for x
   x = 76,046,693.71/9,991.83
6. Step 6: Final answer
   x = 7,610.89