Finding the Fourth Proportional to 1,422.34, 2,131.83 and 641.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.34 : 2,131.83 = 641.43 : x
2. Step 2: Convert to fraction form
   1,422.34/2,131.83 = 641.43/x
3. Step 3: Cross multiply
   1,422.34x = 2,131.83 × 641.43
4. Step 4: Simplify right side
   1,422.34x = 1,367,419.72
5. Step 5: Solve for x
   x = 1,367,419.72/1,422.34
6. Step 6: Final answer
   x = 961.39