Pregunta
upstudy study bank question image url

\( X \) is a normally distributed random variable with mean 41 and standard deviation 22 . What is the probability that \( X \) is less than \( 77 ? \) Write your answer as a decimal rounded to the nearest thousandth.

Ask by Dunn Floyd. in the United States
Jan 24,2025

Solución de tutoría real

Respuesta verificada por el tutor

Responder

The probability that \( X \) is less than 77 is approximately 0.948.

Solución

To find the probability that a normally distributed random variable \( X \) is less than a specific value, we can use the z-score formula and a standard normal distribution table (also known as a z-table). Given: - Mean (\( \mu \)) = 41 - Standard Deviation (\( \sigma \)) = 22 - Value of interest (\( x \)) = 77 First, we need to calculate the z-score for \( x = 77 \) using the formula: \[ z = \frac{x - \mu}{\sigma} \] Substitute the given values into the formula: \[ z = \frac{77 - 41}{22} \] Now, we can calculate the z-score: \[ z = \frac{36}{22} \] \[ z = 1.6363 \] Next, we use the z-score to find the probability that \( X \) is less than 77. We look up the z-score in a standard normal distribution table to find the corresponding probability. The probability that \( X \) is less than 77 is the same as the probability that \( z \) is less than 1.6363. Using a standard normal distribution table, we find that the probability is approximately 0.948. Therefore, the probability that \( X \) is less than 77 is approximately 0.948, rounded to the nearest thousandth.

Revisado y aprobado por el equipo de tutoría de UpStudy

error msg
Explicar
Simplifique esta solución

Mind Expander

To find the probability that \( X \) is less than \( 77 \), we first need to standardize the variable using the Z-score formula: \[ Z = \frac{(X - \mu)}{\sigma} \] Here, \( \mu = 41 \) and \( \sigma = 22 \). Thus, we substitute in the values for \( X = 77 \): \[ Z = \frac{(77 - 41)}{22} = \frac{36}{22} \approx 1.636 \] Now, we can look up the Z-score of \( 1.636 \) in the standard normal distribution table, or use a calculator or software to find the cumulative probability. The cumulative probability for \( Z \approx 1.636 \) is approximately \( 0.9484 \). Therefore, the probability that \( X \) is less than \( 77 \) is: \[ P(X < 77) \approx 0.948 \] So, rounding to the nearest thousandth, the answer is \( 0.948 \).

Latest Probability 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