Finding the Fourth Proportional to 1,461.89, 2,191.55 and 639.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,461.89 : 2,191.55 = 639.52 : x
2. Step 2: Convert to fraction form
   1,461.89/2,191.55 = 639.52/x
3. Step 3: Cross multiply
   1,461.89x = 2,191.55 × 639.52
4. Step 4: Simplify right side
   1,461.89x = 1,401,531.38
5. Step 5: Solve for x
   x = 1,401,531.38/1,461.89
6. Step 6: Final answer
   x = 958.71