Answer:
The 95% confidence interval for the proportion of young adults with pierced tongues who have receding gums is (0.24, 0.506).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
For this problem, we have that:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval for the proportion of young adults with pierced tongues who have receding gums is (0.24, 0.506).
I think it’s c I’m not sure please comment if it’s right so people won’t get it wrong!
8.0% is the answer. To solve these problems just do actual length minus her guess which gives you 0.5. Then divide what you got by the actual length. 0.5 divided by 6.25 is 0.08. Multiply that by 100. 0.08 x 100 is 8 which means the answer is 8.0% :)