C. 8- 6i
(3- i) to the power of 2 (expand the expression)
9- 6 i + i to the power of 2
calculate
9 - 6i - 1
calculate
8- 6i.
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
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905
Brian is 3 years old.
Hope this helps!
X=-9
-x=9 so x=-9 since you inverse the sign
