Read this and answer the question

Richard Sander claims that by artificially elevating minority students into schools they otherwise would not be capable of attending, this discourages them and tends to engender failure and high dropout rates for these students. For example, about half of black college students rank in the bottom 20 percent of their classes, black law school graduates are four times as likely to fail bar exams as are whites, and interracial friendships are more likely to form among students with relatively similar levels of academic preparation; thus, blacks and Hispanics are more socially integrated on campuses where they are less academically mismatched. He claims that the supposed "beneficiaries" of affirmative action minorities do not actually benefit and rather are harmed by the policy. Sander's claims have been disputed, and his empirical analyses have been subject to substantial criticism. A group including some of the country's lead statistical methodologists told the Supreme Court that Sander's analyses were sufficiently flawed that the Court would be wise to ignore them entirely. At the same time many scholars have found that minorities gain substantially from affirmative action.

What is the failure rate for black law school graduates compared to whites for the bar exam?
four times