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.
The mean is the average you're used to, where you add up all the numbers and then divide by the number of numbers. The median is the middle value in the list of number â¦ s. To find the median, your numbers have to be listed in numerical order, so you may have to rewrite your list first.he mean is the average you're used to, where you add up all the numbers and then divide by the number of numbers. The median is the middle value in the list of number â¦ s. To find the median, your numbers have to be listed in numerical order, so you may have to rewrite your list first.