Step-by-step explanation:
For the situation: People who are depressed sleep more, some possible confounding variables could be that sleeping more results in depression to be more likely as they spend less time with people or eating habits may make people more prone to depression and changes their sleeping habits.
For the situation: unmarried men are more likely to end up imprison or a mental institution, it seems like the most likely confounding variable is that more mentally stable people are more likely to get married, so not being married doesn't necessarily cause you to end up in prison or a mental institution, it's just that being mentally unwell may make you more likely to not be married which makes it appear as if being unmarried causes up higher rates in prison and mental institutions.