Finding the Third Proportional to 128,865,831,122 and 261,406,111,748

Step by Step Solution

1. Step 1: Write the proportion equation
   128,865,831,122 : 261,406,111,748 = 261,406,111,748 : x
2. Step 2: Convert to fraction form
   128,865,831,122/261,406,111,748 = 261,406,111,748/x
3. Step 3: Cross multiply
   128,865,831,122x = 261,406,111,748 × 261,406,111,748
4. Step 4: Simplify right side
   128,865,831,122x = 68,333,155,259,207,865,335,808
5. Step 5: Solve for x
   x = 68,333,155,259,207,865,335,808/128,865,831,122
6. Step 6: Final answer
   x = 530,265,894,878.80