A quiz consists of 20 multiple-choice questions find mean and standard deviation

Since the problem is quite vague because the number of choice per question is not written here. I’ll just put for 4 choices and 5 choices each.

To compute for the 5 choices each:

Mean = np = 20 (1/5) = 4

Standard deviation = sqrt (npq) = sqrt (4 * (4/5) = 1.79

To compute for the 4 choices each:

Mean = np = 20 (1/4) = 5

Standard deviation = sqrt (npq) = sqrt (5 * (4/5) = 2