At a large university, 68% of the students have a laptop, while only 43% of professors have one. Let p hat Subscript s and P hat Subscript p be the sample proportions of students and professors, respectively, who have a laptop. Suppose 56 students and 31 professors from this university are selected at random and asked if they have a laptop. Which of the following is the correct calculation and interpretation of the standard deviation of the sampling distribution of p hat Subscript s Baseline minus p hat Subscript p ?

The difference (student – professor) in the sample proportions of those who have a laptop typically varies about 0.012 from the true difference in proportions.
The difference (student – professor) in the sample proportions of those who have a laptop typically varies about 0.035 from the true difference in proportions.
The difference (student – professor) in the sample proportions of those who have a laptop typically varies about 0.109 from the true difference in proportions.
The difference (student – professor) in the sample proportions of those who have a laptop typically varies about 0.25 from the true difference in proportions.