State whether each situation has independent or paired (dependent) samples. 

a. A researcher wants to compare the hand–eye coordination of men and women. She finds a random sample of 50 men and 50 women, asks them to thread a needle, and determines how long they take to do the job. 

b. A researcher wants to know whether professors with tenure have fewer posted office hours than professors without tenure. She observes the number of office hours posted on the doors of tenured and untenured professors.