ID #	Age (years)	Sex (M/F)	Education level (Primary, high school, undergraduate/college)	Family income	High school math grade
1	22	F	Primary	$80,000-$100,000	Missing
2	25	M	Undergraduate/college	$60,000-$80,000	74
3	23	M	Undergraduate/college	>$100,000	76
4	24	F	High school	$80,000-$100,000	73
5	20	F	High school		88
6	24	F	Undergraduate/college	>$100,000	65
7	21	M	High school		74
8	24	F	Undergraduate/college	>$100,000	82
9	22	F	Undergraduate/college	>$100,000	66

Population Sample # of subjects N Mean N Variance $2 N Note: S' is the formula for unbiased sample variance, since we're dividing by a - I. Standard deviation N Note: Finding $ by taking vs reintroduces bias