1. The data in the table below represent warehouse club and superstore sales in the eastern and central United States on a monthly basis. The data are in millions of dollars. (c3p12)

Date	Sales	Date	Sales	Date	Sales	Date	Sales
Jan-02	2,580	Jan-06	4,758	Jan-10	9,183	Jan-14	17,686
Feb-02	2,616	Feb-06	4,914	Feb-10	9,478	Feb-14	17,908
Mar-02	2,838	Mar-06	5,431	Mar-10	10,751	Mar-14	18,691
Apr-02	2,985	Apr-06	5,474	Apr-10	10,518	Apr-14	19,030
May-02	3,258	May-06	6,124	May-10	11,349	May-14	20,623
Jun-02	3,107	Jun-06	6,027	Jun-10	11,728	Jun-14	19,596
Jul-02	3,097	Jul-06	5,914	Jul-10	11,590	Jul-14	20,122
Aug-02	3,288	Aug-06	6,244	Aug-10	11,871	Aug-14	20,029
Sep-02	3,077	Sep-06	5,808	Sep-10	11,336	Sep-14	18,669
Oct-02	3,429	Oct-06	6,373	Oct-10	11,986	Oct-14	20,518
Nov-02	4,011	Nov-06	6,994	Nov-10	13,130	Nov-14	21,967
Dec-02	5,739	Dec-06	9,018	Dec-10	16,694	Dec-14	27,584
Jan-03	2,877	Jan-07	5,694	Jan-11	11,195	Jan-15	19,315
Feb-03	2,885	Feb-07	5,431	Feb-11	10,919	Feb-15	19,186
Mar-03	3,259	Mar-07	6,240	Mar-11	12,389	Mar-15	21,211
Apr-03	3,454	Apr-07	6,101	Apr-11	12,619	Apr-15	20,985
May-03	3,771	May-07	6,849	May-11	13,489	May-15	22,385
Jun-03	3,667	Jun-07	6,694	Jun-11	13,620	Jun-15	22,223
Jul-03	3,743	Jul-07	6,815	Jul-11	13,438	Jul-15	22,602
Aug-03	3,792	Aug-07	6,948	Aug-11	14,084	Aug-15	22,456
Sep-03	3,699	Sep-07	6,450	Sep-11	13,172	Sep-15	21,418
Oct-03	4,082	Oct-07	7,190	Oct-11	14,040	Oct-15	23,092
Nov-03	4,727	Nov-07	7,738	Nov-11	15,759	Nov-15	24,598
Dec-03	6,672	Dec-07	9,769	Dec-11	19,992	Dec-15	30,706
Jan-04	3,560	Jan-08	6,665	Jan-12	13,162	Jan-16	21,692
Feb-04	3,575	Feb-08	6,400	Feb-12	13,394	Feb-16	21,699
Mar-04	4,220	Mar-08	7,277	Mar-12	15,285	Mar-16	23,402
Apr-04	4,282	Apr-08	7,584	Apr-12	14,467	Apr-16	24,046
May-04	4,594	May-08	8,169	May-12	16,086	May-16	24,881
Jun-04	4,691	Jun-08	8,179	Jun-12	16,027	Jun-16	24,602
Jul-04	4,629	Jul-08	8,118	Jul-12	15,622	Jul-16	24,631
Aug-04	4,795	Aug-08	8,284	Aug-12	16,360	Aug-16	24,831
Sep-04	4,632	Sep-08	7,962	Sep-12	14,714	Sep-16	23,603
Oct-04	5,067	Oct-08	8,636	Oct-12	15,894	Oct-16	24,608
Nov-04	5,746	Nov-08	9,433	Nov-12	18,152	Nov-16	26,705
Dec-04	7,965	Dec-08	11,786	Dec-12	22,089	Dec-16	34,023
Jan-05	4,317	Jan-09	8,082	Jan-13	15,161	Jan-17	23,837
Feb-05	4,118	Feb-09	7,761	Feb-13	15,342	Feb-17	23,438
Mar-05	4,855	Mar-09	8,994	Mar-13	16,997	Mar-17	26,305
Apr-05	4,999	Apr-09	8,803	Apr-13	16,623	Apr-17	25,429
May-05	5,343	May-09	9,712	May-13	18,064	May-17	27,152
Jun-05	5,392	Jun-09	9,843	Jun-13	17,605	Jun-17	27,218
Jul-05	5,274	Jul-09	9,769	Jul-13	17,746	Jul-17	26,722
Aug-05	5,435	Aug-09	9,944	Aug-13	18,907
Sep-05	5,217	Sep-09	9,582	Sep-13	16,735
Oct-05	5,460	Oct-09	10,209	Oct-13	18,146
Nov-05	6,288	Nov-09	11,115	Nov-13	20,336
Dec-05	8,403	Dec-09	14,995	Dec-13	24,665