<h2>
Greetings!</h2>
Answer:
Angle A is 118°
Step-by-step explanation:
All angles in a circle add up to 180, so this means that all the measurements of the three angles add to 180:
x + 2x + 13 + x - 8 = 180
Clean it up:
3x + x + x + 13 -8
5x -5 = 180
To isolate the 5x, you need to move the +5 over to the other side, making it a negative 5:
5x = 180 - 5
5x = 175
Now divide each side by 5 to get the value of 1x:

x = 35
So angle A is:
3x + 13
3(35) + 13 = 118
<h3>So angle A is 118°</h3>
<h2>Hope this helps!</h2>
Answer:
The average number of customers in the system is 3.2
Step-by-step explanation:
The average number of customes in the system is given by:

In which
is the number of arirvals per time period
is the average number of people being served per period.
The number of arrivals is modeled by the Poisson distribution, while the service time is modeled by the exponential distribution.
Customers arrive at the stand at the rate of 28 per hour
This means that 
Service times are exponentially distributed with a service rate of 35 customers per hour.
This means that
. So
The average number of customers in the system (i.e., waiting and being served) is


The average number of customers in the system is 3.2
The answer is 0
Let me tell you why
first plug in the numbers
.5(18+14)-(18-14)^2
(9+7)-(4)^2
16-16
0