Finding the Third Proportional to 780.56 and 1,615.69

Step by Step Solution

1. Step 1: Write the proportion equation
   780.56 : 1,615.69 = 1,615.69 : x
2. Step 2: Convert to fraction form
   780.56/1,615.69 = 1,615.69/x
3. Step 3: Cross multiply
   780.56x = 1,615.69 × 1,615.69
4. Step 4: Simplify right side
   780.56x = 2,610,446.10
5. Step 5: Solve for x
   x = 2,610,446.10/780.56
6. Step 6: Final answer
   x = 3,344.31