A study showed a correlation between the number of umbrellas sold at a local store and the number of days of insidsrecess at the nearest school
Which lurking variable would explain the correlation between the number of umbrellas sold and the number of days of inside recess?
A
the size of the sym at the school
Bthe amount of rainfall in the town
Oc the price of umbrellas at the store
On the number of people wearing rain Jackets
O the distance between the school and the store

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.