Question Number 152937 by DELETED last updated on 03/Sep/21
Answered by DELETED last updated on 03/Sep/21
$$\left.\mathrm{4}\right).\:\mathrm{mean}\rightarrow\overset{−} {\mathrm{x}}\:=\frac{\Sigma\mathrm{x}_{\mathrm{i}} ×\mathrm{f}_{\mathrm{i}} }{\Sigma\mathrm{f}_{\mathrm{i}} } \\ $$$$\:\:\:\:\:\overset{−} {\mathrm{x}}=\frac{\mathrm{4}×\mathrm{33}+\mathrm{7}×\mathrm{38}+\mathrm{9}×\mathrm{43}+\mathrm{6}×\mathrm{48}+\mathrm{4}×\mathrm{53}}{\mathrm{30}} \\ $$$$\:\:\:\:\:=\frac{\mathrm{132}+\mathrm{266}+\mathrm{387}+\mathrm{288}+\mathrm{212}}{\mathrm{30}} \\ $$$$\:\:\:\:\:=\frac{\mathrm{398}+\mathrm{675}+\mathrm{212}}{\mathrm{30}}=\frac{\mathrm{1285}}{\mathrm{30}}=\mathrm{42},\mathrm{83}// \\ $$