Question

question 9
the four basic methods used to obtain samples are: random, irregular, cluster, and stratified.
○ true
○ false

question 10
in a frequency distribution of the average age of high school graduates, what would be the boundaries for the class of graduates who were reported to be 18 years old?

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Explanation:

QUESTION 9

The four basic sampling methods are random, systematic, cluster, and stratified. "Irregular" is not a standard sampling method, so the statement is false.

Step1: Understand class boundaries for continuous data

For a class representing a discrete value (like age reported as 18, but age is often treated as continuous in frequency distributions), the boundaries are calculated by taking the midpoint between the previous class's upper limit and the current class's lower limit. For the class of 18 - year - olds (assuming age is measured as a whole number, but in continuous terms), the lower boundary is \(17.5\) and the upper boundary is \(18.5\). This is because values from \(17.5\) up to but not including \(18.5\) would be grouped into the "18 - year - old" class when dealing with whole - number age reporting.

Step2: Confirm the boundary calculation

When we have a class with a discrete value \(x\) (where \(x\) is an integer, for example), the lower boundary is \(x - 0.5\) and the upper boundary is \(x+ 0.5\). For \(x = 18\), the lower boundary is \(18 - 0.5=17.5\) and the upper boundary is \(18 + 0.5 = 18.5\).

Answer:

False

QUESTION 10