Finding the Fourth Proportional to 10,665.75, 15,991.78 and 4,430.07

Step by Step Solution

1. Step 1: Write the proportion equation
   10,665.75 : 15,991.78 = 4,430.07 : x
2. Step 2: Convert to fraction form
   10,665.75/15,991.78 = 4,430.07/x
3. Step 3: Cross multiply
   10,665.75x = 15,991.78 × 4,430.07
4. Step 4: Simplify right side
   10,665.75x = 70,844,704.82
5. Step 5: Solve for x
   x = 70,844,704.82/10,665.75
6. Step 6: Final answer
   x = 6,642.26