Question

13 multiple choice 6.67 points a standardized test at ohs is given to 1600 of its students. it is known to be normally distributed with a mean of 500 and a standard deviation of 110. how many students scored at most 450? (se aplica una prueba estandarizada en ohs a 1600 de sus estudiantes. se sabe que tiene una distribución normal con una media de 500 y una desviación estándar de 110. ¿cuántos estudiantes obtuvieron como máximo 450?) 575 522 545 1081 previous

Explanation:

Step1: Calculate the z - score

The z - score formula is $z=\frac{x-\mu}{\sigma}$, where $x = 450$, $\mu=500$, and $\sigma = 110$. So $z=\frac{450 - 500}{110}=\frac{- 50}{110}\approx - 0.45$.

Step2: Find the cumulative probability

Using a standard normal distribution table (or z - table), the cumulative probability $P(Z\leq - 0.45)$ is approximately $0.3264$.

Step3: Calculate the number of students

Multiply the cumulative probability by the total number of students. So the number of students is $0.3264\times1600 = 522.24\approx522$.

Answer:

B. 522