Finding the Fourth Proportional to 9,991.83, 13,787.15 and 5,742.07

Step by Step Solution

1. Step 1: Write the proportion equation
   9,991.83 : 13,787.15 = 5,742.07 : x
2. Step 2: Convert to fraction form
   9,991.83/13,787.15 = 5,742.07/x
3. Step 3: Cross multiply
   9,991.83x = 13,787.15 × 5,742.07
4. Step 4: Simplify right side
   9,991.83x = 79,166,749.52
5. Step 5: Solve for x
   x = 79,166,749.52/9,991.83
6. Step 6: Final answer
   x = 7,923.15