QUESTION IMAGE
Question
the librarian measured the thickness of the textbooks in the school library. taking a selection of 6 books, he recorded the following thicknesses: 2 centimeters, 6 centimeters, 2 centimeters, 2 centimeters, 2 centimeters, 6 centimeters. what was the standard deviation of the textbooks thicknesses? if the answer is a decimal, round it to the nearest tenth. standard deviation (σ): centimeters
Explicación:
Paso1: Calcular la media
Tenemos los datos: 2, 6, 2, 2, 2, 6. La media $\bar{x}=\frac{2 + 6+2+2+2+6}{6}=\frac{20}{6}=\frac{10}{3}\approx3.33$.
Paso2: Calcular el cuadrado de la diferencia con la media para cada dato
Para $x_1 = 2$: $(2 - \frac{10}{3})^2=(\frac{6 - 10}{3})^2=(-\frac{4}{3})^2=\frac{16}{9}$
Para $x_2 = 6$: $(6-\frac{10}{3})^2=(\frac{18 - 10}{3})^2=(\frac{8}{3})^2=\frac{64}{9}$
Para $x_3 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_4 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_5 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_6 = 6$: $(6-\frac{10}{3})^2=\frac{64}{9}$
Paso3: Calcular la varianza
La varianza $s^2=\frac{\sum_{i = 1}^{n}(x_i-\bar{x})^2}{n}$. Aquí $n = 6$.
$\sum_{i = 1}^{6}(x_i-\bar{x})^2=\frac{16}{9}+\frac{64}{9}+\frac{16}{9}+\frac{16}{9}+\frac{16}{9}+\frac{64}{9}=\frac{16\times4 + 64\times2}{9}=\frac{64+128}{9}=\frac{192}{9}=\frac{64}{3}\approx21.33$.
$s^2=\frac{\frac{64}{3}}{6}=\frac{64}{18}=\frac{32}{9}\approx3.56$.
Paso4: Calcular la desviación estándar
La desviación estándar $s=\sqrt{s^2}=\sqrt{\frac{32}{9}}=\frac{\sqrt{32}}{3}=\frac{4\sqrt{2}}{3}\approx1.9$.
Respuesta:
1.9
Snap & solve any problem in the app
Get step-by-step solutions on Sovi AI
Photo-based solutions with guided steps
Explore more problems and detailed explanations
Explicación:
Paso1: Calcular la media
Tenemos los datos: 2, 6, 2, 2, 2, 6. La media $\bar{x}=\frac{2 + 6+2+2+2+6}{6}=\frac{20}{6}=\frac{10}{3}\approx3.33$.
Paso2: Calcular el cuadrado de la diferencia con la media para cada dato
Para $x_1 = 2$: $(2 - \frac{10}{3})^2=(\frac{6 - 10}{3})^2=(-\frac{4}{3})^2=\frac{16}{9}$
Para $x_2 = 6$: $(6-\frac{10}{3})^2=(\frac{18 - 10}{3})^2=(\frac{8}{3})^2=\frac{64}{9}$
Para $x_3 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_4 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_5 = 2$: $(2 - \frac{10}{3})^2=\frac{16}{9}$
Para $x_6 = 6$: $(6-\frac{10}{3})^2=\frac{64}{9}$
Paso3: Calcular la varianza
La varianza $s^2=\frac{\sum_{i = 1}^{n}(x_i-\bar{x})^2}{n}$. Aquí $n = 6$.
$\sum_{i = 1}^{6}(x_i-\bar{x})^2=\frac{16}{9}+\frac{64}{9}+\frac{16}{9}+\frac{16}{9}+\frac{16}{9}+\frac{64}{9}=\frac{16\times4 + 64\times2}{9}=\frac{64+128}{9}=\frac{192}{9}=\frac{64}{3}\approx21.33$.
$s^2=\frac{\frac{64}{3}}{6}=\frac{64}{18}=\frac{32}{9}\approx3.56$.
Paso4: Calcular la desviación estándar
La desviación estándar $s=\sqrt{s^2}=\sqrt{\frac{32}{9}}=\frac{\sqrt{32}}{3}=\frac{4\sqrt{2}}{3}\approx1.9$.
Respuesta:
1.9