During the last 2 years , statistics finals have been done online . Each year there have been a few technical problems . The professor has offered to review what happened in each case to see if adjustments are appropriate . However , when a technical problem occurred , the student had to request this adjustment . Last year , 12 students had technical problems , and 5 requested a review for adjustment . This year only 8 students had technical problems , and 3 requested an adjustment . The professor wants to know if there is a significant difference in the proportion of students requesting this adjustment . To do that, he is requesting that you calculate the Z score for this difference. a) Cannot be calculated because it does not meet the necessary conditions . b)The proportions are clearly different . c)Z = .905 d)Z = 0.816497