Answer:

Step-by-step explanation:



Answer:
x = -3
Step-by-step explanation:
3x –7 = -16
3x = -16 + 7
3x = -9
x = -3
Answer: About 191 students scored between a 60 and an 80.
Step-by-step explanation:
Given : A set of 200 test scores are normally distributed with a mean of 70 and a standard deviation of 5.
i.e.
and 
let x be the random variable that denotes the test scores.
Then, the probability that the students scored between a 60 and an 80 :

The number of students scored between a 60 and an 80 = 0.9544 x 200
= 190.88 ≈ 191
Hence , about 191 students scored between a 60 and an 80.
Yes it is true
Hope this helps
N³ - 2n² - 15n = 0
"n"
n (n² + 2n - 15) = 0
n = 0
n² + 2n - 15 = 0
Δ = (2)² - 4(1)(-15)
Δ = 4 + 60 = 64
n' = (-2+8) / 2 = 6/2 =3
n'' = (-2-8) / 2 = -10/2 = -5
Solution:
S {-5 , 0 , 3 }