Finding the Fourth Proportional to 1,419.05, 2,128.04 and 639.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,419.05 : 2,128.04 = 639.02 : x
2. Step 2: Convert to fraction form
   1,419.05/2,128.04 = 639.02/x
3. Step 3: Cross multiply
   1,419.05x = 2,128.04 × 639.02
4. Step 4: Simplify right side
   1,419.05x = 1,359,867.04
5. Step 5: Solve for x
   x = 1,359,867.04/1,419.05
6. Step 6: Final answer
   x = 958.29