Chapter 3 Exercise 6 7 & 8 Notes

Exercise 6. Results from a survey on current status of Iranian women in workplaces are presented in the following table. The survey involves 1500 women and 1500 men. Employment sectors Male Female Manufacturing 665 673 Agriculture 347 671 Service 488 156 a. What kind of graph would you use in order to graphically compare the two distributions? In this case we have a quantitative discrete variable so to show the data graphically we use a BAR PLOT. As the sample size is the same for both female and male, in the y-axis we can have the absolute frequencies. 1° way to represent Women Men MA5 Exercise 7. Suppose in a small Italian village there are 200 families. We record the number of private vehicles in each family. The results are summarized in the table below. N. of family vehicles numerical discrete 0 9 1 33 2 74 3 45 4 25 5 14 200 a. How many private vehicles in the village? (33-1)+(74-2)+(45.3)+(25-4)+(14.5)=486 total number of vehicles b. What percentage of families has exactly 3 vehicles? 45/200 * 100 = 22.5% c. What percentage of families has more than 3 vehicles? And less than 3 vehicles? (25+14)/200 * 100 = 19.5% (9+33+74)/200 * 100 = 58% d. Display data graphically and describe the shape of the dataset [Image of a bell-shaped curve] central density the space is symmetrical e. What percentage of families has a number of vehicles between 2 and 4? (74+45+25)/200 * 100 = 72% Exercise 8. The following data represent life (in hours) of a sample of 40 100-watt light bulbs produced by the manufacturer A and by the manufacturer B. Manufacturer A Manufacturer B 684 720 723 821 819 836 888 897 103 831 835 848 852 852 907 912 918 942 143 859 860 868 870 876 952 959 962 986 992 915 105 100 911 994 1004 1005 1007 1015 922 924 926 926 938 1016 1018 1020 1022 1034 939 943 946 954 971 1038 1072 1077 1077 1082 972 1977 984 1005 1014 1096 1100 1113 1113 1116 1016 1011 1052 1080 1093 1153 1054 1174 1188 1230 a. Construct a frequency distribution and a percentage distribution for each manufacturer, using a suitable class interval width. Manufacturer A i ni % Wi Fi Fi% 15 [600,700) 2 5% 100 2 5% [700,800) 2 5% 100 4 10% [800,900) 13 32.5% 100 17 42.5% [900, 1000) 16 40% 100 33 82.5% [1000, 1100) 7 17.5% 100 40 100% Manufacturer B i ni % Wi Fi Fi% 15 [800,900) 4 10% 100 4 10% [900, 1000) 12 30% 100 16 40% [1000, 1100) 16 40% 100 32 80% [1100, 1200) 7 17.5% 100 39 97.5% [1200, 1300) 1 2.5% 100 40 100% c. Manufacturer B