Finding the Third Proportional to 871.59 and 1,915.31

Step by Step Solution

1. Step 1: Write the proportion equation
   871.59 : 1,915.31 = 1,915.31 : x
2. Step 2: Convert to fraction form
   871.59/1,915.31 = 1,915.31/x
3. Step 3: Cross multiply
   871.59x = 1,915.31 × 1,915.31
4. Step 4: Simplify right side
   871.59x = 3,668,421.97
5. Step 5: Solve for x
   x = 3,668,421.97/871.59
6. Step 6: Final answer
   x = 4,208.87