Bob is building a wooden cabin. the cabin is 30 meters wide. he obtained a bunch of 17 meters long wooden beams for the roof of the cabin. naturally, he wants to place the roof beams in such an angle that each pair of opposite beams would meet exactly in the middle. what is the angle of elevation, in degrees, of the roof beams? round your final answer to the nearest tenth.

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.