Finding the Fourth Proportional to 9,870.86, 13,621.96 and 5,394.80

Step by Step Solution

1. Step 1: Write the proportion equation
   9,870.86 : 13,621.96 = 5,394.80 : x
2. Step 2: Convert to fraction form
   9,870.86/13,621.96 = 5,394.80/x
3. Step 3: Cross multiply
   9,870.86x = 13,621.96 × 5,394.80
4. Step 4: Simplify right side
   9,870.86x = 73,487,749.81
5. Step 5: Solve for x
   x = 73,487,749.81/9,870.86
6. Step 6: Final answer
   x = 7,444.92