In robert's grade, 1/3 of the students have a sister. of the students who have a sister, 1/2 also have a brother. what fraction of the students in robert's grade have both a sister and a brother?

For each of the following, mark whether it is a possible confounder (a factor that mixes up the results, making it look like candy is to blame when it's a causal (or causation) link which supports the argument that candy causes criminal behavior (ie, explains how candy leads to criminality ), or neither (an irrelevant factor, something that may cause people to become criminals but has nothing to do with eating candy). choose your answers based only< on the information given. additives in candy- additives found in candy may adversely affect brain development of young children in ways that could contribute towards adult aggression. impulsive personality-- kids who are highly impulsive and have trouble delaying gratification are more likely to eat candy every day as children and more likely to disobey laws as adults. violent abuse-- children who suffer violent abuse are more likely to become violent adults and commit violent crimes. gender- boys are overwhelmingly more likely to commit violent crimes

Which steps are important when designing and conducting a scientific experiment? hide the results from fellow scientists. identify the independent variable. eliminate all dependent variables. address any confounding variables. form a non-falsifiable hypothesis.

How did geographical features create a civilization in china