136k views
4 votes
A recent public opinion poll on gun control found that 82 people interviewed out of the 160 interviews supported new gun regulations.

What is the 90% confidence interval?

What is the 95% confidence interval?

User Swateek
by
8.1k points

1 Answer

4 votes

1) The 90% confidence interval shows that between 0.444 and 0.581 proportion of people support new gun regulations.

2) Similarly, the 95% confidence interval shows that between 0.444 and 0.581 proportion of people support new gun regulations.

How the confidence intervals are constructed:

We use the confidence interval formula as follows:

CI = p ± z*(sqrt(p*(1-p)/n))

Where:

The confidence interval = CI

The sample proportion = p

The sample size = n

The z-score corresponding to the desired confidence level = z.

1) For a 90% confidence level, the z-score is 1.645. Given that 82 people interviewed out of the 160 interviews supported new gun regulations, we can calculate the sample proportion as follows:

p = 82/160

= 0.5125

Substituting the value of p, n = 160, and z = 1.645 in the confidence interval formula, we can calculate the confidence interval as follows:

CI = 0.5125 ± 1.645*(sqrt(0.5125*(1-0.5125)/160))

≈ (0.444, 0.581)

2) At 95% confidence interval, the sample proportion is:

p = 82/160

= 0.5125

Substituting the value of p, n = 160, and z = 1.96 in the confidence interval formula, we can calculate the confidence interval as follows:

CI = 0.5125 ± 1.96*(sqrt(0.5125*(1-0.5125)/160))

≈ (0.444, 0.581)

Therefore, we can be both 90% and 95% confident that the true proportion of people who support new gun regulations falls between 0.444 and 0.581.

User Chkas
by
8.5k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories