155-160 6 157.5 2 12 160-165 5 162.5 3 13 Mean=a+h x =147.5+5 x 23/51 =147.5+115/51 =(147.5+2.255)cm=149.755cm Let us find median of the data:- Class of height (in Frequency number of girls Cumulative cm) frequency 135-140 4 4 140-145 7 11=cf 145-150 18=f 29 150-155 11 40 155-160 6 46 160-165 5 51 Total n we have median class (145-150) it gives l=145,h=5,f=18,cf=11 median=l+ x h=145 + x5 =145+14.5 x5 18 =145+4.028 =149.028cm Let us find mode of the data:- Class of heights (in cm) FREQUENCY (No of Girls) 135-140 4 140-145 7=f1 (Modal class) 145-150 18=fm Modal class is 145-150 150-155 11=f2 Thus l=145, h=5, fm=18, f1=7, f2=11 155-160 6 160-165 5 Mode=H xh=145 + x 5 Total 51 =145+55/18 =145+3.055 =148.055 cm CONCLUSION:- Mean=149.755, median=149.028 and mode=148.055 3x median=3x149.028=447.084 Mode + 2 x mean=148.055+2x149.755 =148.055+299.510=447.565 Thus we have verified that 3x median =mode + 2 x mean(Approx) ACTIVITY – 5
155-160 160-165 6 5 157.5 162.5 2 3 12 13 Mean=a+h x =147.5+5 x 23/51 =147.5+115/51 =(147.5+2.255)cm=149.755cm Let us find median of the data:- Class of height (in cm) Frequency number of girls Cumulative frequency 135-140 140-145 145-150 150-155 155-160 160-165 4 7 18=f 11 6 5 4 11=cf 29 40 46 51 Total n we have median class (145-150) it gives l=145,h=5,f=18,cf=11 median=l+ x h=145 + x5 =145+14.5 x5 18 =145+4.028 =149.028cm Let us find mode of the data:- Class of heights (in cm) FREQUENCY (No of Girls) 135-140 140-145 145-150 150-155 155-160 160-165 4 7=f1 18=fm 11=f2 6 5 Total 51 (Modal class) Modal class is 145-150 Thus l=145, h=5, fm=18, f1=7, f2=11 Mode=H xh=145 + x 5 =145+55/18 =145+3.055 =148.055 cm CONCLUSION:- Mean=149.755, median=149.028 and mode=148.055 3x median=3x149.028=447.084 Mode + 2 x mean=148.055+2x149.755 =148.055+299.510=447.565 Thus we have verified that 3x median =mode + 2 x mean(Approx) ACTIVITY – 5
1288508582final_study_material_maths_class_x_2012-2013.docx