Finding the Fourth Proportional to 9,991.50, 13,788.27 and 5,575.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991.50 : 13,788.27 = 5,575.50 : x
2. Step 2: Convert to fraction form
   9,991.50/13,788.27 = 5,575.50/x
3. Step 3: Cross multiply
   9,991.50x = 13,788.27 × 5,575.50
4. Step 4: Simplify right side
   9,991.50x = 76,876,499.39
5. Step 5: Solve for x
   x = 76,876,499.39/9,991.50
6. Step 6: Final answer
   x = 7,694.19