Finding the Fourth Proportional to 5,619.86, 8,428.72 and 2,109.72

Step by Step Solution

1. Step 1: Write the proportion equation
   5,619.86 : 8,428.72 = 2,109.72 : x
2. Step 2: Convert to fraction form
   5,619.86/8,428.72 = 2,109.72/x
3. Step 3: Cross multiply
   5,619.86x = 8,428.72 × 2,109.72
4. Step 4: Simplify right side
   5,619.86x = 17,782,239.16
5. Step 5: Solve for x
   x = 17,782,239.16/5,619.86
6. Step 6: Final answer
   x = 3,164.18