Answer:
(a) The expected score is 12.8
(b) The standard deviation is 3.2 and variance is 10.24
Step-by-step explanation:
Consider the provided information.
You are to take a multiple-choice exam consisting of 64 questions with 5 possible responses to each question.
Here n=64 p=1/5 and q=1-1/5=4/5
Part (a) we need to find the expected score on the exam.
Expected = np
Expected score = number of questions × P(right)
Hence, the expected score is 12.8
Part (b) Compute the variance and standard deviation of x.
Standard Deviation:
Now calculate the standard deviation as shown:
Variance:
Hence, the standard deviation is 3.2 and variance is 10.24