Two dentists A and B make a survey of the Mate of the teeth
     Two dentists A and B make a survey of the Mate of the teeth of 200 children in a village. Dr. A selects a simple random sample of 20 children and counts the number of decayed teeth for each child. with the following results.  Dr. B, using the same dental techniques, examines ail 200 children. recording merci y those who have no decayed teeth. He finds 60 children with no decayed teeth. Estimate the total number of decayed teeth in the village children  Using A\'s results only  Using both A\'s and B\'s results  Are the estimates unbiased?  Which estimate do you expect to be more precise? 
  
  Solution

