Question

A simple random sample of 100 students is to be drawn from a middle school of 800 students, to check how many students have not had at least one dose of the 3 recommended doses of the HPV vaccine 28. The standard error of the sample percentage of those who have not been vaccinated is at most (select the smallest correct answer) (a) 1% (b) 2% (c) 3% (d) 4% (e) 29. It turns out that when the sample is drawn, 65 children had not received any dose of the HPV vaccine. The sample percentage of non-vaccinated children is closest to (a) 10% (b) 30% (c) 50% (d) [70%] (e) 90%

Answer 1

28)

Answer)

When we are not given with the population proportion, then we take the best estimate = 0.5

Standard error is given by

S.E = √{(p*(1-p))/n}

P = 0.5

N = 100

After substituting the values,

Standard error = √{(0.5*(1-0.5))/100)}

Standard error = √0.0025 = 0.05

5%

So, therefore the correct answer here is 5%

Answer 29)

Sample proportion = 65/(sample size)

Sample size = 100

Therefore, sample proportion = 65/100 = 0.65

Or 65%

And this is closest to 70%