Researchers are comparing the intelligence levels of incoming freshmen and graduating seniors. Assuming that there is not a systematic difference in intelligence levels between the two groups and researchers reject the null hypothesis, they have committed:

Type 1 error

Explanation:

In statistics and research, a type 1 error results when a researcher rejects a true null hypothesis and accepts the alternate hypothesis instead.

From this question let's say the null hypothesis is there is no systematic difference between two groups

And the alternate says there is systematic difference between two groups.

We commit a type 1 error when we reject the null hypothesis which is correct and accept the alternate hypothesis which is false.

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 !

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.