Finding the Third Proportional to 78,321 and 117,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,321 : 117,139.50 = 117,139.50 : x
2. Step 2: Convert to fraction form
   78,321/117,139.50 = 117,139.50/x
3. Step 3: Cross multiply
   78,321x = 117,139.50 × 117,139.50
4. Step 4: Simplify right side
   78,321x = 13,721,662,460.25
5. Step 5: Solve for x
   x = 13,721,662,460.25/78,321
6. Step 6: Final answer
   x = 175,197.74