6. Statistical Inference
Confidence Intervals — Quiz
Test your understanding of confidence intervals with 5 practice questions.
Practice Questions
Question 1
Which of the following statements about a confidence interval is true?
Question 2
What is the effect of increasing the confidence level on the width of a confidence interval, assuming all other factors remain constant?
Question 3
When constructing a confidence interval for a population mean, if the population standard deviation ($\sigma$) is known, which distribution is used to find the critical value?
Question 4
A sample of 50 students is taken, and their mean score on a test is 80 with a standard deviation of 5. What is the standard error of the mean?
Question 5
A 95% confidence interval for the proportion of people who own a smartphone is calculated as $(0.75, 0.85)$. What is the margin of error for this interval?