Discrete vs. Continuous Data

1. Discrete Data

Usain Bolt is widely considered the greatest sprinter of all time. Let's consider some data on Mr. Bolt

• Gold medals: 8
• World records: 3
• 100 meter time: 9.58 seconds
• Weight: 207 lbs

The number of rail cars in a train and shoe sizes are also example of discrete data. You can have half size shoe sizes, but that's all you can have. You can't have quarter size shoe sizes, or eighth of size shoe sizes, or 0.01 shoe sizes. You can't say that you're a size 9 and an eighth. So there are only certain values that shoe size can take. That makes it discrete.

term to know

Discrete Data

Data that can only take so many different values.

2. Continuous Data

Now the difference between discrete and continuous is continuous data can take any value within a range. Some examples of data that are continuous are temperature, commute time, and wait. With all of these examples, you can take on any value within a range. So for instance, suppose you're talking about daytime temperature.

The daytime temperature could be something between 50 and 80 degrees on a summer's day, and it takes on any value between those. Same with commute time. One day it might take you 30 minutes and five seconds to get to work. The next day it might take you 32 minutes and 17 seconds.

And weight, one person might weigh 150.75 pounds, and one person might weigh 102.62 pounds. They can take on any value within a spectrum. As opposed to discrete values can only take certain values within a spectrum.

term to know

Continuous Data

Data that can take any value within an interval.

3. Discrete and Continuous Data in Practice

Determine if each situation is discrete or continuous.

watch

try it

Determine if the following are discrete or continuous.

Is barometric pressure discrete or continuous?

You should have said that barometric pressure is continuous because it can take any value within a certain range, usually somewhere around 30.

Is the number of pairs of shoes someone owns discrete or continuous?

Discrete. You can't have half a pair--I suppose you can half a pair of shoes if you've lost one--but you can't have any number of pairs of shoes within a certain range. Typically, it takes only whole number values.

Is the time for a light bulb to burn out discrete or continuous?

That's continuous. It could take any length of time from zero seconds all the way to a couple of years.

Question: Number of green M&Ms in a bag?
Answer: Discrete. Typically, again, we're dealing only with whole number values.