maker model type A 1001 pc A 1002 pc A 1003 pc A 2004 laptop A 2005 laptop A 2006 laptop B 1004 pc B 1005 pc B 1006 pc B 2007 laptop C 1007 pc D 1008 pc D 1009 pc D 1010 pc D 3004 printer D 3005 printer E 1011 pc E 1012 pc E 1013 pc E 2001 laptop E 2002 laptop E 2003 laptop E 3001 printer E 3002 printer E 3003 printer F 2008 laptop F 2009 laptop G 2010 laptop H 3006 printer H 3007 printer Figure 2.20: Sample data for Product model speed ram hd price 1001 2.66 1024 250 2114 1002 1003 2.10 512 250 1.42 512 995 80 478 1004 2.80 1024 250 649 1005 3.20 512 250 630 1006 3.06 3.20 1024 320 1049 1007 2.20 1024 200 510 1008 2.20 2048 250 770 1009 2.00 1024 250 1010 2.80 2048 300 1011 1.86 2048 160 1012 2.80 1024 160 1013 650 770 959 649 512 80 529 (a) Sample data for relation PC model speed ram hd screen price 2001 2.00 2048 240 20.1 3673 2002 1.73 1024 80 17.0 949 2003 1.80 512 60 15.4 549 2004 2.00 512 2005 2.16 1024 120 2006 2.00 2048 80 60 13.3 1150 17.0 2500 15.4 1700 2007 1.83 1024 120 2008 1.60 1024 100 15.4 2009 1.60 512 80 14.1 2010 2.00 2048 160 15.4 13.3 1429 900 680 2300 (b) Sample data for relation Laptop model color type price 3001 true ink-jet 99 3002 false 3003 true 3004 true 3005 false 3006 true laser 239 laser 899 ink-jet 120 laser 120 ink-jet 100 3007 true laser 200 (c) Sample data for relation Printer Figure 2.21: Sample data for relations of Exercise 2.4.1 !g) Find those pairs of PC modeis that have both the same speed and RAM. A pair should be listed only once; e.g., list (i, j) but not (j, i). !! h) Find those manufacturers of at least two different computers (PC's or laptops) with speeds of at least 2.80. !! i) Find the manufacturer(s) of the computer (PC or laptop) with the highest available speed. !! j) Find the manufacturers of PC's with at least three different speeds. !! k) Find the manufacturers who sell exactly three different models of PC.