Question

Poderiam responder essas 2 questões de estatística, eu não consegui chegar ao resultado

735babc8f0c2bbb2159481a2b8e51f87.pdf

Answer 1

$6)\ Amostra:\\n=100\\fx = 19(0)+23(1)+25(2)+12(3)+14(4)+7(5)= 200\\ fx^2=19(0)^2+23(1)^2+35(2)^2+12(3)^2+14(4)^2+7(5)^2=630\\ M\'edia:\\ \bar{x} = \dfrac{\sum{fx}}{n}= \dfrac{200}{100}=2\\\\ Desvio\ Padr\~ao:\\ S^2=\dfrac{\sum{fx^2}-n\bar{x}^2}{n-1}\\ S^2=\dfrac{630-100(2)^2}{100-1}=\dfrac{230}{99}\\ S=\sqrt{\dfrac{230}{99}}\\ S\approx1,5242\\\\ Coeficiente\ de\ Varia\c{c}\~ao:\\ CV\approx\dfrac{1,5242}{100} \times 100 \approx 1,5242\%\\ \boxed{CV\approx1,52\%}$

$7)\ Popula\c{c}\~ao:\\\\ fx^2=5(300)^2+6(700)^2+7(1100)^2+2(1500)^2=16.360.000\\\\M\'edia:\\ \mu = \dfrac{\sum{fx}}{n}= \dfrac{16.400}{20}=820\\\\Desvio\ Padr\~ao:\\ \sigma^2=\dfrac{\sum{fx^2}}{n}-\mu^2\\ \sigma^2=\dfrac{16.360.000}{20}-672.400=145.600\\ \sigma=\sqrt{145.600}\\ \sigma\approx381,57\\\\ Coeficiente\ de\ Varia\c{c}\~ao:\\ CV=\dfrac{\sigma}{\mu}\approx\dfrac{381,57}{820} \times 100\\ \boxed{CV \approx 46,53\%}$

Espero que ajude.
Bons estudos!