You are taking a class with a large number of students.The professor notes that the midterm exam scores were bell-shaped but doesn't tell you the mean.You take a random sample of 10 students and construct a 95% confidence interval for the mean exam score.Now the professor wants to give everyone 5 extra points on the exam.How will your confidence interval change?
A)The sample mean will increase by 5 points and the margin of error will also.
B)The sample mean will increase by 5 points but the margin of error will stay the same.
C)The sample mean will stay the same but the margin of error will increase by 5 points.
D)Both the sample mean and the margin of error will remain unchanged.

Question

Quizplus · Accepted Answer

Adding 5 points to every student's score will increase the overall mean by 5 points. However, since the margin of error is based on the standard deviation and sample size, it will stay the same. Therefore, the confidence interval will simply shift up by 5 points, but the range (i.e. the margin of error) will remain unchanged.

You Are Taking a Class with a Large Number of Students.The