Answer: option d.
Step-by-step explanation:
You have the following formul given in the problem:

You know that:
The number of customers serviced in an hour by the technical support representative is 6 costumbers, therefore:

As the problem asked for the probability that a costumber will be on hold less than 30 minutes, we know that:

Substitute the values above into the formula.
Then, you obtain:
or 95%
Hey there!
A perpendicular line's slope to another line is always the negative reciprocal of slope.
If our line has a slope of two, we first must find the reciprocal, which is 1/2. Then, we put a negative on it.
Therefore, our equation is y=-1/2x+b.
I hope that this helps! Have a great day!
Statistics is not an exact science, meaning that with any answer, there will be variance. This is because the sample size used to obtain values is always smaller than the population being studied.
-ax-20=-14
add 20 to both sides
-ax=6