Question

The physics scores of 200 students follow a normal distribution with a mean of 75 and standard deviation of 7. Which conclusion is best supported by this information?
A. About 32 students have a score higher than 89.
B. About 5 students have a score higher than 89.
C. About 100 students have a score higher than 89.
D. About 4 students have a score lower than 89.
E. About 32 students have a score lower than 89.

Answer 1

the correct answer is A cuz the score has 2 be higher than 89

Answer 2

Answer:

About 5 students have a score higher than 89.

Step-by-step explanation:

Given : The physics scores of 200 students follow a normal distribution with a mean of 75 and standard deviation of 7.

To Find: Which conclusion is best supported by this information?

Solution:

Mean = $\mu=7$

Standard deviation = $\sigma = 7$

n = 200

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

Substitute the values.

$z = \frac{89-75}{7}$

$z = 2$

So, P(z<2)=0.9772

So, P(z<89)=$200 \times 0.9772=195.44$

So, 195 students have score less than 89

So, Remaining 5 students have score higher than 89.

So, Option B is true.

Hence About 5 students have a score higher than 89.