Answer:
The 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, 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:
Of 150 adults selected randomly from one town, 30 of them smoke. This means that 
99% confidence interval
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 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).