Finding the Third Proportional to 615.09 and 899.86

Step by Step Solution

1. Step 1: Write the proportion equation
   615.09 : 899.86 = 899.86 : x
2. Step 2: Convert to fraction form
   615.09/899.86 = 899.86/x
3. Step 3: Cross multiply
   615.09x = 899.86 × 899.86
4. Step 4: Simplify right side
   615.09x = 809,746.89
5. Step 5: Solve for x
   x = 809,746.89/615.09
6. Step 6: Final answer
   x = 1,316.46