Question

"Tongue Piercing May Speed Tooth Loss, Researchers Say" is the headline of an article. The article describes a study of 51 young adults with pierced tongues. The researchers found receding gums, which can lead to tooth loss, in 16 of the participants.

(a) Construct a 95% confidence interval for the proportion of young adults with pierced tongues who have receding gums. (Round your answers to three decimal places.)

( , )

(b) What assumptions must be made for use of the z confidence interval to be appropriate? (Select all that apply.)

1) The sample is voluntary.

2) The sample is a random sample.

3) The sample is independent.

4) The sample size is large.

Answer 1