To get the number of standard deviation that 77 is from the mean, we get the z-score:
z-score is given by
z=(x-μ)/σ
where:
μ-mean
σ-standard deviation
thus the value of z from the information above is:
x=77
μ=58
σ=7
z=(77-58)/7=2.7143
P(-3)= -2(-3) -2
p(-3)= 6-2
p(-3)= 4
Answer:

The number is 8 because 
And if you add 4, you get 20
Hence, the number is 8
Answer:
60 students passed, and 75 appeared in examination.
Step-by-step explanation:
Let's say s is the total number of students and p is the number of students who passed.
80% of the students passed, so:
0.8 s = p
If there were 10 less passers, and 15 less students (5 less failures), then the ratio of passers to failures would be 5/1.
(p − 10) / (s − p − 5) = 5 / 1
Simplify the second equation:
p − 10 = 5 (s − p − 5)
p − 10 = 5s − 5p − 25
6p = 5s − 15
Substitute the first equation.
6 (0.8 s) = 5s − 15
4.8 s = 5s − 15
0.2 s = 15
s = 75
p = 0.8 s
p = 60
60 students passed, and 75 appeared in examination.
Answer:
A. y = -x -2
Step-by-step explanation:
thanks for the questions.