Harvey’s teacher assigns classroom jobs by having students pick job tickets out of a box. there are 21 tickets for line leader, 11 tickets for paper passer and 18 tickets for board cleaner. if harvey randomly selects a ticket from the box, what is the probability that he will pull out a ticket for line leader?

Arandomized controlled trial is designed to evaluate the effect of metoprolol in patients with heart failure. while preparing for statistical analysis, the researcher reviews some common types of statistical errors. which of the following statements is true regarding a type i error in a clinical study? a. the study is not significantly powered to detect a true difference between study groups. bthe null hypothesis is true but is rejected in error. c. the null hypothesis is false but is accepted in error. d. type i error is also known as beta and is usually 0.1 or 0.2. e. type i error depends on the study's confidence interval.