1 Record or upload your video. 2  At the end of the video processing stage in the upload interface, you will see an option to choose a Custom thumbnail under the Video thumbnails section. 3  Go to your channel Video Manager. 4  Locate a video and click the Edit button. 5  Click the Custom thumbnail button and upload a thumbnail.
Median is the middle number of a given dataset (if itÃÂ­s odd) while average is a definition of arithmetic mean, which is the most oft-cited average. The value of median depends on the number of elements in a data set (odd or even) while average does not.
median-relating to or constituting the middle value of an ordered set of values (or the average of the middle two in a set with an even number of values); the median value of 17, 20, and 36 is 20; the median income for the year was $15,000.