Answer to Question #178599 in Statistics and Probability for Nicolas Flavio

Question

Classify the following random variables as discrete or continuous.

1. The number of cellphone units of GHI Mobile Company sold on a given day

2. The number of correct answers in a 50-item multiple choice test

3. The number of nonproductive hours in an eight-hour workday

4. The length of life (in hours) of a light bulb 5 . The number of vehicular accidents each year in Cainta, Rizal

Answer 1

1. The number of cellphone units of GHI Mobile Company sold on a given day is Discrete  variable. Because the number of cellphone units are countable. Being countable is one of the main characteristics of discrete random variable.

2. The number of correct answers in a 50-item multiple choice test is Discrete variable. All correct answers correspond to whole number points, which is countable. The number of correct answers can be countable, so it classified as the discrete random variable.

3. The number of nonproductive hours in an eight-hour workday is Continuous variable. Number of hours can be decimal, but not an integer that’s why it can’t meet main bases of being discrete random variable. Number of nonproductive hours in a working day is obtained by measuring, so classified as a continuous random variable.

4. The length of life (in hours) of a light bulb is also a Continuous random variable. Because it is related to time and the variable time varies over the entire line of real numbers that can’t be countable.

5. The number of vehicular accidents each year in Cainta, Rizal can be a Discrete variable. Because it involves counting the number of events (accidents) that consists only whole numbers rather than numbers with decimals.