We have been given that Tina designed an electric skateboard that has a speed of 4 miles per hour. Further we are given that in one hour it travels 4 miles, and in 2 hours it travels 8 miles.
We know that speed of any object can be found at any time, irrespective of it being a complete hour or a fractional hour. Therefore, speed of the electric skateboard is an example of continuous data.
The that in one hour it travels 4 miles, and in 2 hours it travels 8 miles have been given so that someone can easily confuse the speed of electric skateboard as a discrete data, but in actual speed of skateboard is a continuous data.