Sales of cement manufacturing companies are a continuous variable. This means that the sales can take on any value within a certain range, rather than being limited to specific values.

Explanation:

Continuous variables are those that can take on any value within a certain range. For example, the height of a person is a continuous variable because it can take on any value between a certain range (such as between 4 feet and 7 feet). In the case of sales of cement manufacturing companies, the sales can take on any value within a certain range, such as between $1 million and $100 million. This is because sales can vary depending on a number of factors, such as market demand, competition, and economic conditions.

Discrete variables, on the other hand, are those that can only take on specific values. For example, the number of children in a family is a discrete variable because it can only take on specific values (such as 1, 2, 3, etc.). In the case of sales, if the sales could only take on specific values (such as $1 million, $2 million, $3 million, etc.), then it would be a discrete variable.

Attributes are characteristics or properties of a variable that can be used to describe it. For example, the attributes of the sales variable could include the company's name, the time period in which the sales were recorded, and the location of the company.

In conclusion, the sales of cement manufacturing companies are a continuous variable because they can take on any value within a certain range.