C={z | z is an even integer greater than 26 and less than or equal to 30}

and

Step-by-step explanation:

Let's understand what the question is asking.

"A value C is equal to the value of z such that the value z is an even integer greater than 26 and less than or equal to 30."

The only even values in this range:

are 28 and 30. The reason why 30 is included is because z is an integer greater than 26 and less than or equal to 30.

So your answer would be:

and

You can also write it as:

C = {28, 30} if asked to answer in set notation.

the answer is a

step-by-step explanation:

because if you put 1 in to the square root of x it equals 300.

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.