Finding the Third Proportional to 780 and 1,180.50

Step by Step Solution

1. Step 1: Write the proportion equation
   780 : 1,180.50 = 1,180.50 : x
2. Step 2: Convert to fraction form
   780/1,180.50 = 1,180.50/x
3. Step 3: Cross multiply
   780x = 1,180.50 × 1,180.50
4. Step 4: Simplify right side
   780x = 1,393,580.25
5. Step 5: Solve for x
   x = 1,393,580.25/780
6. Step 6: Final answer
   x = 1,786.64