I need help I will give a lot of points it is easy

Bob the builder is making 480kg of cement mix. this is made by cement, sand and gravel in the ratio 1: 3: 4

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.

Answer 20 points and brainiest ! on the board, your teacher writes an example of how to find the median. one of the numbers is erased, leaving what is shown, 18, 30, 26,12 22. what is the median? a. 10 b. 20 c. 24 d. 28