This lecture explains the Non-parametric test: SIGN TEST for small and large samples.
Other Non-parametric tests
Sample Rank Correlation-Coefficient: https://youtu.be/USqlzYkAdAM
Mann-Whitney U-test: https://youtu.be/eZP1nFlVejM
Wilcoxon Signed-Rank Test: https://youtu.be/sJvRbLel4oM
Sign Test: https://youtu.be/i2hExvzkuGI