Pregunta
upstudy study bank question image url

The scores on a psychology exam were normally distributed with a
of 62 and a standard deviation of 8 . A failing grade on the exam wa
anything 2 or more standard deviations below the mean. What was
cutoff for a failing score? Approximately what percentage of the
students failed?
The cutoff for a failing score was 46 .
(Simplify your answer.)
Approximately percent of the students failed.
(Round to one decimal place as needed.)

Ask by Beck Collins. in the United States
Jan 20,2025

Solución de inteligencia artificial de Upstudy

Respuesta verificada por el tutor

Responder

The cutoff for a failing score is 46. Approximately 2.3% of the students failed.

Solución

To determine the cutoff for a failing score and the percentage of students who failed, let’s break down the problem step by step.

Given:

  • Mean (μ) = 62
  • Standard Deviation (σ) = 8
  • Failing Grade = 2 or more standard deviations below the mean

1. Cutoff for a Failing Score:

The cutoff score is calculated as:
So, the cutoff for a failing score is 46.

2. Percentage of Students Who Failed:

We need to find the percentage of students scoring 46 or below. Since the scores are normally distributed, we can use the standard normal distribution (Z-score) to find this percentage.
Calculate the Z-score:
Find the corresponding percentile for :
Using standard normal distribution tables or a calculator:
Rounding to one decimal place:

Final Answer:

Approximately 2.3 % of the students failed.

Respondido por UpStudy AI y revisado por un tutor profesional

error msg
Explicar
Simplifique esta solución

The Deep Dive

To find the cutoff for a failing score, you’ll subtract 2 standard deviations from the mean. Given a mean of 62 and a standard deviation of 8:
Cutoff = Mean - (2 × Standard Deviation) = 62 - (2 × 8) = 62 - 16 = 46.
Now, regarding the percentage of students who failed, you can refer to the properties of a normal distribution. About 95% of the scores should fall within two standard deviations of the mean, which means approximately 5% of students scored below 46, marking them as failing.
So, the percentage of students who failed is approximately 5.0%.

preguntas relacionadas

Latest Statistics Questions

¡Prueba Premium ahora!
¡Prueba Premium y hazle a Thoth AI preguntas de matemáticas ilimitadas ahora!
Quizas mas tarde Hazte Premium
Estudiar puede ser una verdadera lucha
¿Por qué no estudiarlo en UpStudy?
Seleccione su plan a continuación
Prima

Puedes disfrutar

Empieza ahora
  • Explicaciones paso a paso
  • Tutores expertos en vivo 24/7
  • Número ilimitado de preguntas
  • Sin interrupciones
  • Acceso completo a Respuesta y Solución
  • Acceso completo al chat de PDF, al chat de UpStudy y al chat de navegación
Básico

Totalmente gratis pero limitado

  • Solución limitada
Bienvenido a ¡Estudia ahora!
Inicie sesión para continuar con el recorrido de Thoth AI Chat
Continuar con correo electrónico
O continuar con
Al hacer clic en "Iniciar sesión", acepta nuestros términos y condiciones. Términos de Uso & Política de privacidad