The experiment that involved a group of laboratory rats being allowed to breed without limit in a confined space in order to study the effects of crowding was conducted by

A clinically depressed individual who has been threatening suicide finally shows diminishing of depressive symptoms. This person's risk of committing suicide:

A) has increased dramatically; almost no one who is depressed commits suicide until she or he is recovering. B) may have increased, since the person may have the energy to act on the suicidal impulse. C) probably has decreased, although a slight risk remains. D) has decreased substantially; almost no one who is depressed commits suicide once recovery from depression is under way.

When all of the scores in a distribution are transformed to z scores, the shape of that distribution is changed from what it was before.

a. true b. false