## How do you interpret t test confidence intervals?

A normal 95% CI for a difference of means = 0.25 would be something smaller like 0.20 to 0.30 where you could say if my difference of means is 0.25 then the true mean is probably somewhere between 0.20 and 0.30. Your test shows true mean between 0.02 to 0.48 which is a huge range. Run a t.

What is the 95% confidence interval for the population proportion?

Because you want a 95 percent confidence interval, your z*-value is 1.96.

Which is the correct way to interpret a 95% confidence interval?

The correct interpretation of a 95% confidence interval is that “we are 95% confident that the population parameter is between X and X.”

### How do you interpret a population proportion?

For example, let’s say you had 1,000 people in the population and 237 of those people have blue eyes. The fraction of people who have blue eyes is 237 out of 1,000, or 237/1000. The letter p is used for the population proportion, so you would write this fact like this: p = 237/1000.

How do you conclude a confidence interval?

We can use the following sentence structure to write a conclusion about a confidence interval: We are [% level of confidence] confident that [population parameter] is between [lower bound, upper bound]. The following examples show how to write confidence interval conclusions for different statistical tests.

What do confidence intervals tell us?

What does a confidence interval tell you? he confidence interval tells you more than just the possible range around the estimate. It also tells you about how stable the estimate is. A stable estimate is one that would be close to the same value if the survey were repeated.

#### How do you interpret upper and lower confidence intervals?

The narrower the interval (upper and lower values), the more precise is our estimate. As a general rule, as a sample size increases the confident interval should become more narrow.

How do you find the confidence interval for a population proportion?

To use the standard error, we replace the unknown parameter p with the statistic p̂. The result is the following formula for a confidence interval for a population proportion: p̂ +/- z* (p̂(1 – p̂)/n)0.5. Here the value of z* is determined by our level of confidence C.