• Merge the first three. After the merge, you should have two years of annual state of residence data for four individuals.
• Assume that the age variable is for 2010. Now we have an error in the data, as people would have been a year older in 2011. Try replacing the ages to reflect this.
• Question (a): What is the average age of individuals in the sample during 2010? How about during 2011?
• Question (b): What are the standard deviations (SD) of ages during 2010 and 2011?
• Question (c): For your answer to part (b) above, How different are the two SDs? Do you find this to be surprising? Why or why not?

person	age	sex	_merge	year	state
A	21	male	Matched (3)
B	57	female	Matched (3)
C	35	male	Matched (3)
D	23	female	Matched (3)
A	21		.
B	57		.
C	35		.
D	23		.
A		male	.
B		female	.
C		male	.
D		female	.
A			.	2010	CA
A			.	2011	TX
B			.	2010	OR
B			.	2011	OR
C			.	2010	IN
C			.	2011	CA
D			.	2010	MI
D			.	2011	OR
A			.	2010	CA
A			.	2011	TX
B			.	2010	OR
B			.	2011	OR
C			.	2010	IN
C			.	2011	CA
D			.	2010	MI
D			.	2011	OR
E	44		.
F	29		.
G	32		.
H	55		.