Concept #1: Determining the Small Sample Confidence Interval for a Population Mean
Concept #2: Determining the Small Sample Confidence Interval for a Population Mean: Intro
Practice: Books get more and more expensive every semester. 25 randomly selected students in your school spent, on average $500 with a standard deviation of $50. Construct a 98% confidence interval for the true spending on books.
Practice: People always purchase gifts on Black Friday. The average spending on this day is $1,000 with a standard deviation of $256. These estimates are based on a sample of 16 randomly selected Americans. Construct a 95% confidence interval for the true spending of Americans on Black Friday.
Practice: College students are said to binge drink more than any other population of young adults. You randomly select 9 people in your school and find that the average number of drinks consumed each week is 10 with a standard deviation of 5. Construct a 90% confidence interval for the true average number of drinks college students at your school consumer each week.