Finding the Fourth Proportional to 3,620.45, 5,428.64 and 1,428.59

Step by Step Solution

1. Step 1: Write the proportion equation
   3,620.45 : 5,428.64 = 1,428.59 : x
2. Step 2: Convert to fraction form
   3,620.45/5,428.64 = 1,428.59/x
3. Step 3: Cross multiply
   3,620.45x = 5,428.64 × 1,428.59
4. Step 4: Simplify right side
   3,620.45x = 7,755,300.82
5. Step 5: Solve for x
   x = 7,755,300.82/3,620.45
6. Step 6: Final answer
   x = 2,142.08