Answer:
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905
Step-by-step explanation:
The scenario presented can be modeled by a binomial model;
The probability of success is, p = 0.65
There are n = 80 independent trials
Let X denote the number of drivers that wear a seat belt, then we are to find the probability that X is greater than 42;
Pr(X > 42)
In this case we can use the normal approximation to the binomial model;
mu = n*p = 80(0.65) = 52
sigma^2 = n*p*(1-p) = 18.2
Answer: (x) =
f(x) = 9x - 8 , to find the inverse of f(x) , replace f(x) with y , then the equation becomes
y = 9x - 8 , then make x , the subject of the formula ,
9x = y + 8
x =
Finally , replace x , with (x) and y with x , so we have
(x) =
Answer: 30^2 * pi = 2827.43.
Full proof below