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
8.0k 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
8.4k points