Finding the Fourth Proportional to 9,897.86, 13,658.54 and 5,420.75

Step by Step Solution

1. Step 1: Write the proportion equation
   9,897.86 : 13,658.54 = 5,420.75 : x
2. Step 2: Convert to fraction form
   9,897.86/13,658.54 = 5,420.75/x
3. Step 3: Cross multiply
   9,897.86x = 13,658.54 × 5,420.75
4. Step 4: Simplify right side
   9,897.86x = 74,039,435.31
5. Step 5: Solve for x
   x = 74,039,435.31/9,897.86
6. Step 6: Final answer
   x = 7,480.35