Finding the Fourth Proportional to 2,100.26, 3,150.86 and 639.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.26 : 3,150.86 = 639.52 : x
2. Step 2: Convert to fraction form
   2,100.26/3,150.86 = 639.52/x
3. Step 3: Cross multiply
   2,100.26x = 3,150.86 × 639.52
4. Step 4: Simplify right side
   2,100.26x = 2,015,037.99
5. Step 5: Solve for x
   x = 2,015,037.99/2,100.26
6. Step 6: Final answer
   x = 959.42