Finding the Fourth Proportional to 2,123.01, 3,184.48 and 642.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123.01 : 3,184.48 = 642.20 : x
2. Step 2: Convert to fraction form
   2,123.01/3,184.48 = 642.20/x
3. Step 3: Cross multiply
   2,123.01x = 3,184.48 × 642.20
4. Step 4: Simplify right side
   2,123.01x = 2,045,073.06
5. Step 5: Solve for x
   x = 2,045,073.06/2,123.01
6. Step 6: Final answer
   x = 963.29