Chapter 3, Problem CS

To determine

To explain: Whether 54% provides an indication that the majority of the American adults sensed that childhood vaccination is important.

Answer to Problem CS

Solution: There is 95% chance that approximately half of the adult Americans support childhood vaccination.

Explanation of Solution

In the Gallup poll, 1015 adults are interviewed who are chosen randomly for the study. The percentage of people who support childhood vaccination is obtained as 54%.

As the value is obtained on the basis of the sample, it may vary if another set of sample is considered. So, a percentage of error is allowed for the study. The margin of error in plus or minus 4% points provides that the value will vary between 50% and 58%. However, it may be possible that the value is outside the range for some samples. For that, the experimenter includes another condition before providing the conclusion about the study, which is that there is 95% chance that the result will lie between 50% and 58%.

Therefore, it can be said that there is 95% chance that there are 50% to 58% of adult Americans who believe that childhood vaccination is important, that is, approximately half of the Americans support childhood vaccination for any sample.