**Answer:**

The 90% confidence interval is (0.1897, 0.2285).

**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:**

From a July 2019 survey of 1186 randomly selected Americans ages 18-29, it was discovered that 248 of them vaped (used an e-cigarette) in the past week. This means that

**Construct a 90% confidence interval to estimate the population proportion of Americans age 18-29 who vaped in the past week.**

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 90% confidence interval is (0.1897, 0.2285).