Answer:
a. The percentage of vehicles who pass through this construction zone who are exceeding the posted speed limit =90.82%
b. Percentage of vehicles travel through this construction zone with speeds between 50 mph and 55 mph= 2.28%
Step-by-step explanation:
We have to find
a) P(X>40)= 1- P(x=40)
Using the z statistic
Here
x= 40 mph
u= 44mph
σ= 3 mph
z=(40-44)/3=-1.33
From the z-table -1.67 = 0.9082
a) P(X>40)=
Probability exceeding the speed limit = 0.9082 = 90.82%
b) P(50<X<55)
Now
z1 = (50-44)/3 = 2
z2 = (55-44)/3= 3.67
Area for z>3.59 is almost equal to 1
From the z- table we get
P(55 < X < 60) = P((50-44)/3 < z < (55-44)/3)
= P(2 < z < 3.67)
= P(z<3.67) - P(z<2)
= 1 - 0.9772
= 0.0228
or 2.28%
Answer:
Step-by-step explanation:
Consider right triangle ΔABC with legs AC and BC and hypotenuse AB. Draw the altitude CD.
1. Theorem: The length of each leg of a right triangle is the geometric mean of the length of the hypotenuse and the length of the segment of the hypotenuse adjacent to that leg.
According to this theorem,

Let BC=x cm, then AD=BC=x cm and BD=AB-AD=3-x cm. Then

Take positive value x. You get

2. According to the previous theorem,

Then

Answer: 
This solution doesn't need CD=2 cm. Note that if AB=3cm and CD=2cm, then

This means that you cannot find solutions of this equation. Then CD≠2 cm.
Answer:
-3 and -2
Step-by-step explanation:
A better explanation...
(positive)(positive)= positive
(positive)(negative)= negative
(negative)(negative)= positive
(negative)(positive)= negative