Finding the Fourth Proportional to 9,855.02, 13,599.99 and 5,378.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,855.02 : 13,599.99 = 5,378.72 : x
2. Step 2: Convert to fraction form
   9,855.02/13,599.99 = 5,378.72/x
3. Step 3: Cross multiply
   9,855.02x = 13,599.99 × 5,378.72
4. Step 4: Simplify right side
   9,855.02x = 73,150,538.21
5. Step 5: Solve for x
   x = 73,150,538.21/9,855.02
6. Step 6: Final answer
   x = 7,422.67