Combine the like terms to create an equivalent expression.
7n+4n

Apark is in the shape of a rectangle. the park authorities are planning to build a 2-meter-wide jogging path in the park (shown as the shaded region in the image). what is the area of the jogging path? plz

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.

What ratio is proportional to 18/21