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:
B) 5 hours
Step-by-step explanation:
First, find the amount of mph between 60 and 80:
80 - 60
= 20 mph
Since the speed increases 4 mph per hour, we can find how long it will take to get to 80 mph by dividing 20 by 4:
20/4
= 5
So, the correct answer is B, 5 hours
Answer:
x = -1/2 and -2
Step-by-step explanation:
Solve for <em>x</em>: Move all terms to the left side and set equal to zero. Then set each factor equal to zero.
Using the quadratic formula: Solve the equation for x by finding a, b, and c of the quadratic then applying the quadratic formula.