Confidence Intervals Flashcards
What is the purpose of a confidence interval?
To estimate the range within which a population parameter is likely to fall.
True or False: A confidence interval provides a single value estimate of a population parameter.
False
Fill in the blank: A confidence interval is often expressed as a range of values around a sample _____ .
mean
What does a 95% confidence interval imply?
There is a 95% probability that the interval contains the true population parameter.
Multiple Choice: Which of the following is NOT a factor that affects the width of a confidence interval?
The color of the data points
What is the formula for calculating a confidence interval for a population proportion?
p̂ ± Z * √(p̂(1-p̂)/n)
True or False: A larger sample size will generally lead to a narrower confidence interval.
True
What does the ‘Z’ in the confidence interval formula represent?
The Z-score corresponding to the desired confidence level.
Fill in the blank: The sample proportion is denoted by _____ .
p̂
What is the relationship between confidence level and the width of the confidence interval?
A higher confidence level results in a wider confidence interval.
Multiple Choice: If the confidence interval for a population proportion is (0.45, 0.55), what is the point estimate?
0.50
True or False: Confidence intervals can be used for both means and proportions.
True
What does it mean if a confidence interval does not contain the value of zero for a difference in proportions?
It suggests that there is a statistically significant difference between the proportions.
What are the key components needed to calculate a confidence interval for a population proportion?
Sample proportion, sample size, and Z-score.
Fill in the blank: A confidence interval is an estimate of the _____ of a population parameter.
uncertainty
