Question

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%

Answer 1

Answer:

59%

Step-by-step explanation:

Mean = $\mu = 500$

Standard deviation = $\sigma = 110$

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

Formula : $z = \frac{x-\mu}{\sigma}$

at x = 350

$z = \frac{350-500}{110}$

$z =−1.36$

at x = 550

$z = \frac{550-500}{110}$

$z =0.454$

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%

Answer 2

The answer is C.) 59 percent