Respuesta :
Answer:
0.081,0.2621,0.645,0.919
Step-by-step explanation:
Let X be the average speed of a car driving down freeway
Given that X is normal with mean as 70mph with a standard deviation of 5mph.
To convert to Z score we do
[tex]Z =\frac{x-70}{5}[/tex]
a) the probability that a randomly selected car is driving more than 77mph
[tex]=P(X>77)\\=P(Z>1.4)\\=0.081[/tex]
b) probability that a randomly selected car is driving between 65 and 69 mph
= [tex]P(-1<z<-0.2)\\=0.2621[/tex]
c) the probability that a randonly selected car is driving between 67 and 77mph
=[tex]P(-0.6<z<1.4)\\\\=0.645[/tex]
d) the probability that a randomly selected car is driving less than 77mph
[tex]=P(Z<1.4) = 0.919[/tex]
