the scores of the students on a standardized test are normally distributed with a mean of 500 and a standard deviation of 110 what is the probability that a randomly selected student has a test score between 350 and 550 use the portion of the standard normal cable below to answer the question
A. 7%
B. 9%
C. 59%
D. 91%

Respuesta :

the answer is C.) 59 percent

Answer:

59%

Step-by-step explanation:

Mean = [tex]\mu = 500[/tex]

Standard deviation = [tex]\sigma = 110[/tex]

We are supposed to find 0 what is the probability that a randomly selected student has a test score between 350 and 550

Formula : [tex]z = \frac{x-\mu}{\sigma}[/tex]

at x = 350

[tex]z = \frac{350-500}{110}[/tex]

[tex]z =−1.36[/tex]

at x = 550

[tex]z = \frac{550-500}{110}[/tex]

[tex]z =0.454[/tex]

So, P(-1.36<z<0.454)

P(z<0.45)-P(z<-1.36)

Using z score table

= 0.6736-0.0869

= 0.5867

= 58.6% ≈ 59%

Thus the probability that a randomly selected student has a test score between 350 and 550 is 59%