Étudier l'écart-type d'un échantillon de taille n d’une loi de probabilité Exercice

\sigma(X_1) = \sqrt{p(1-p)}

\sigma(X_1) = p(1-p)

\sigma(X_1) = \sqrt{p}

\sigma(X_1)= \sqrt{1-p} 

\sigma\left( \sum_{i=1}^n X_i \right) = \sqrt{np(1-p)}

\sigma\left( \sum_{i=1}^n X_i \right) = n \sqrt{p(1-p)}

\sigma\left( \sum_{i=1}^n X_i \right) = \sqrt{np}

\sigma\left( \sum_{i=1}^n X_i \right)= np(1-p) 

\sigma(M_n)= \sqrt{\dfrac{p(1-p)}{n}}

\sigma(M_n)= \dfrac{\sqrt{p(1-p)}}{n}

\sigma(M_n)= \sqrt{\dfrac{1-p}{n}}

\sigma(M_n)= \sqrt{\dfrac{p^2 − p}{n}}

\sigma(M_n)= \dfrac{\sigma}{\sqrt{n}} 

\sigma(M_n)= \sigma \sqrt{n} 

\sigma(M_n) = \sigma^2 \sqrt{n} 

\sigma(M_n)= \sigma n