Finding the Fourth Proportional to 1,419.15, 2,128.72 and 445.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,419.15 : 2,128.72 = 445.33 : x
2. Step 2: Convert to fraction form
   1,419.15/2,128.72 = 445.33/x
3. Step 3: Cross multiply
   1,419.15x = 2,128.72 × 445.33
4. Step 4: Simplify right side
   1,419.15x = 947,982.88
5. Step 5: Solve for x
   x = 947,982.88/1,419.15
6. Step 6: Final answer
   x = 667.99