Finding the Fourth Proportional to 9,000.42, 12,420.24 and 5,645.00

Step by Step Solution

1. Step 1: Write the proportion equation
   9,000.42 : 12,420.24 = 5,645.00 : x
2. Step 2: Convert to fraction form
   9,000.42/12,420.24 = 5,645.00/x
3. Step 3: Cross multiply
   9,000.42x = 12,420.24 × 5,645.00
4. Step 4: Simplify right side
   9,000.42x = 70,112,192.70
5. Step 5: Solve for x
   x = 70,112,192.70/9,000.42
6. Step 6: Final answer
   x = 7,789.88