Finding the Third Proportional to 3,985 and 5,691.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,985 : 5,691.50 = 5,691.50 : x
2. Step 2: Convert to fraction form
   3,985/5,691.50 = 5,691.50/x
3. Step 3: Cross multiply
   3,985x = 5,691.50 × 5,691.50
4. Step 4: Simplify right side
   3,985x = 32,393,172.25
5. Step 5: Solve for x
   x = 32,393,172.25/3,985
6. Step 6: Final answer
   x = 8,128.78