Schools roundup

One Comment

  • In the post on disparate outcome in school discilpine is a statement:
    ” For example, blacks, who are only 13% of America’s population, commit nearly half of all murders — four times the general rate.”

    No..

    Let N be the total population, x the homicide rat for the population, b the homicide rate for blacks, and o theh homicide rate for others.

    Then .13 X N X b + .87 X N X o = .N X x. (N cancels out. Divide by x.) .
    .13 X (b/x) + .87 X (o/x) = .1
    .13 X N X b = .50 X N X x. (N cancels out. Divide by x.)
    .13 (b/x) = .50.
    b/x = 3.85 (This is where the 4 comes from.)
    .87 X (o/x) = .50
    .13 X (b/x) = .87 (o/x)
    b/o = .87/ .13 = 6.7.