Finding the Third Proportional to 645,120 and 902,290.50

Step by Step Solution

1. Step 1: Write the proportion equation
   645,120 : 902,290.50 = 902,290.50 : x
2. Step 2: Convert to fraction form
   645,120/902,290.50 = 902,290.50/x
3. Step 3: Cross multiply
   645,120x = 902,290.50 × 902,290.50
4. Step 4: Simplify right side
   645,120x = 814,128,146,390.25
5. Step 5: Solve for x
   x = 814,128,146,390.25/645,120
6. Step 6: Final answer
   x = 1,261,979.39