Finding the Third Proportional to 612,091.50 and 918,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   612,091.50 : 918,139.50 = 918,139.50 : x
2. Step 2: Convert to fraction form
   612,091.50/918,139.50 = 918,139.50/x
3. Step 3: Cross multiply
   612,091.50x = 918,139.50 × 918,139.50
4. Step 4: Simplify right side
   612,091.50x = 842,980,141,460.25
5. Step 5: Solve for x
   x = 842,980,141,460.25/612,091.50
6. Step 6: Final answer
   x = 1,377,212.63