The average breaking strength of steel rods is required to be at least 35,000 psi. Based on historical information, the standard deviation of breaking strength is 1,500 psi. A random sample of 4 specimens had the strength: piece one was 32,000, piece two was 36,000, piece three was 34,000, and piece four was 34,500. Which of the following hypothesis tests would you conduct?a.One sample t Testb.One sample Chi-square Testc.One sample Z Testd.One sample F Test
Question
The average breaking strength of steel rods is required to be at least 35,000 psi. Based on historical information, the standard deviation of breaking strength is 1,500 psi. A random sample of 4 specimens had the strength: piece one was 32,000, piece two was 36,000, piece three was 34,000, and piece four was 34,500. Which of the following hypothesis tests would you conduct?a.One sample t Testb.One sample Chi-square Testc.One sample Z Testd.One sample F Test
Solution
Para determinar cuál prueba de hipótesis es adecuada, sigamos los siguientes pasos:
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Identificar la hipótesis nula y alternativa:
- Hipótesis nula (): La media de la resistencia a la rotura de las varillas de acero es al menos 35,000 psi.
- Hipótesis alternativa (): La media de la resistencia a la rotura de las varillas de acero es menor a 35,000 psi.
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Calcular la media muestral ():
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Determinar el error estándar de la media ():
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Calcular el estadístico de prueba: Dado que conocemos la desviación estándar poblacional (), utilizamos la prueba Z.
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Decidir la prueba de hipótesis adecuada:
- La prueba t de una muestra se usa cuando la desviación estándar poblacional no es conocida y el tamaño de la muestra es pequeño.
- La prueba Chi-cuadrado de una muestra se usa para pruebas de varianza.
- La prueba F de una muestra se usa para comparar dos varianzas.
- La prueba Z de una muestra se usa cuando la desviación estándar poblacional es conocida y el tamaño de la muestra es suficientemente grande o la distribución es normal.
Dado que conocemos la desviación estándar poblacional y estamos probando la media de una muestra, la prueba adecuada es:
c. One sample Z Test
Similar Questions
The average breaking strength of steel rods is required to be at least 35,000 psi. Based on historical information, the standard deviation of breaking strength is 1,500 psi. A random sample of 4 specimens had the strength: piece one was 32,000, piece two was 36,000, piece three was 34,000, and piece four was 34,500. What will be null and alternate hypothesis in this case?a.H0: µ = 35,000 psi and H1: µ ≠ 35,000 psib.H0: µ ≥ 35,000 psi and H1: µ < 35,000 psic.H0: µ > 35,000 psi and H1: µ < 35,000 psid.H0: µ ≥ 35,000 psi and H1: µ = 35,000 psi
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