Confidence Intervals

Front

Margin of Error is equal to: Standard Deviation, 2 * Standard Deviation, Critical Value, Point Estimate

Back

2 * Standard Deviation

Front

True or False: The more confident you want to be, the smaller your confidence interval will be.

Back

False

Front

Which of the following changes to a study would result in a smaller confidence interval?
Options:
increasing the confidence level, increasing the sample size;
increasing the confidence level, decreasing the sample size;
decreasing the confidence level, decreasing the sample size;
decreasing the confidence level, increasing the sample size.

Back

decreasing the confidence level, increasing the sample size.

Front

Which z-value is used for a 95% confidence interval?

Back

1.96

Front

The amount added and subtracted to the statistic.

Back

Margin of Error

Front

What is the margin of error for the interval (6.8, 12.9)?

Back

3.05

Front

The height of women is normally distributed with an average height of 64 inches and a standard deviation of 2.5 inches. What interval contains 99.7% of all data? Options: 61.5 to 66.5, 56.5 to 71.5, 59 to 69, 2.5 to 99.7

Back

56.5 to 71.5

Front

Identify the confidence interval used in the figure below if each shaded area is equal to 0.05.

Back

90%

Front

A research company wants to estimate the proportion of people who like oatmeal with a 95% confidence level. They get 325 people to sign up for the survey, but only 250 show up. What happens to the confidence interval?

Back

It gets larger.

Front

A recent study of 750 Internet users in Europe found that 35% of Internet users were women. What is the 95% confidence interval of the true proportion of women in Europe who use the Internet? Options: 0.321 < p < 0.379, 0.316 < p < 0.384, 0.309 < p < 0.391, 0.305 < p < 0.395

Back

0.316 < p < 0.384