Ralph is 3 times as old as sarah. in six years, ralph will be only twice as old is sarah will be then. find ralphs age now.

if x represents sarah's age now, which of the following expressions represents ralphs age in six years?

a: 2x
b: 6x
c: 2x+6
d: 3x+6

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.