Question

A researcher would like to evaluate the claim that large doses of vitamin C can help prevent the common cold. One group of participants is given a large does of the vitamin (500 mg per day), and a second group is given a placebo (sugar pill). The researcher records the number of colds each individual experiences during the 3-month winter season. Is the dependent variable (number of colds within a winter season) discrete or continuous?

Answer 1

Answer: The dependent variable is discrete.

Step-by-step explanation:

There are different types of variables. Variables can be classified into two main groups: qualitative and quantitative.

Qualitative variables are those who represent attributes. For example, flowers of 3 different colors: yellow, orange and blue. Also, when they haven’t an order or a hierarchy, they are called nominal, as in the previous flowers's example. When they have a hierarchy associated, they are called ordinal (you can distinguish a natural order), for example: small, medium, large.  

Quantitative variables are those that represent quantities, and they can be discrete or continuous. A variable is discrete when only certain finite values ​​are possible. This variables are used to represent counts, like the in the example: number of colds within a winter season, or for example, number of students in a class, number of plants per acre, etc.

On the other hand, when a variable is continuous, infinite values ​​can be found between two values. They are measure in continuous scales. For example, the plant’s height: it could be take any continuous values, like 10.3 cm, 15 cm, 17.99 cm.

In summary, in the present problem the response variable is quantitative and discrete, because it is countable and finite, and only some values ​​are possible: positive integers.