Answer:

Step-by-step explanation:

Answer:
Percentage of computers working equals:
90%
Step-by-step explanation:
Three of the thirty computers are out of service.
Number of computers working=30-3=27
Total computers=30
Percentage of working computers=
=
= 90%
Hence, Percentage of computers working is:
90%
We are looking to find P(X>60 students)
X is normally distributed with mean 50 and standard deviation 5
We need to find the z-score of 60 students

To find the probability of P(Z>2), we can do 1 - P(Z<2)
So we read the probability when Z<2 which is 0.9772, then subtract from one we get 0.0228
The number of students that has score more than 60 is 0.0228 x 1000 = 228 students
2[5+2(8-6)]
2[5+2(2)]
2[5+4]
2[9]
18