Answer:
a) It can be used because np and n(1-p) are both greater than 5.
Step-by-step explanation:
Binomial distribution and approximation to the normal:
The binomial distribution has two parameters:
n, which is the number of trials.
p, which is the probability of a success on a single trial.
If np and n(1-p) are both greater than 5, the normal approximation to the binomial can appropriately be used.
In this question:

So, lets verify the conditions:
np = 201*0.45 = 90.45 > 5
n(1-p) = 201*(1-0.45) = 201*0.55 = 110.55 > 5
Since both np and n(1-p) are greater than 5, the approximation can be used.
Answer:
$6.48
Step-by-step explanation:
It would be $6.48 because 1.60 times 4 1/2 is 7.2 and if you do 10% of 7.2 you get B.
Answer:
The function is increasing for all real values of x where
x < –4.
Step-by-step explanation:
we have

This is a vertical parabola open downward (the leading coefficient is negative)
The vertex (h,k) represent a maximum
The roots of the function (or x-intercepts) are x=-6 and x=-2
The x-coordinate of the vertex is the midpoint of the roots
so

The y-coordinate of the vertex is
substitute the x-coordinate of the vertex in the quadratic equation



The vertex is the point (-4,4)
The function is increasing in the interval (-∞,-4)
The function is decreasing in the interval (-4,∞)