Research has found that people are happiest when they have hours a day of face-to-face contact with others.

the median of the data is 4.

step-by-step explanation:

the median means the middle number of a given number.

to decide which one is the median, arrange in ascending or descending order. but sometimes, you may find two(2) number in the middle, but it's easy, just add them together and divide by 2.

so,   determine the median of the data. 2, 3, 3, 4, 5, 7, 9

it is already arranged, count 3 times forward and 3 backward and the one left is your answer.

2,3,3,4,5,7,9

our answer is 4.

hope this !

c. wright mills's sociological imagination suggest investigating to explain this increase?

permafrost layer, it exists beneath a layer of soil, rock or sediment.