A recent study showed that, in one year, 86% of all blacks slain were slain by blacks and 78% of all whites slain were slain by whites. Let y denote race of victim and x denote race of murderer.
a) Which conditional distributions do these statistics refer to, those of y at given catagories of x, or those of x at given categories of y? Set up a table with race of murderers as rows and race of victims as columns, showing the two conditional distributions.
b) Are x and y independent or dependent? Explain.