It is 1 in 4
Countries like Egypt and Morocco are in Africa and have few black folks
It is not 1 in 4. The population of North Africa is less than 250 million people and that includes them adding in Sudan, which are clearly Black people.
Northern Africa Population 2020 (Demographics, Maps, Graphs)
The population of the continent of Africa is 1.3 billion people. Even if you believe the wildest estimates of Nigeria's population of around 200 million people or there bout that is still far less than 25%, which is what 1 in 4 is.