Answer:
67.2 centimeters
Step-by-step explanation:
From the graph of a quadratic equation, you can find:
The roots. These are the points where the graph crosses the x-axis, and is the solution of the quadratic equation when y=0. Usually, there are either two or zero.
The coefficient of the leading term. In the quadratic equation y= ax^2 + bx + c,
the parabola points upward if a is positive, and downward if a is negative.
The vertex. You can find the vertex, or where the two sides of the parabola meet, by looking at the graph.
Answer:
a) 3.47% probability that there will be exactly 15 arrivals.
b) 58.31% probability that there are no more than 10 arrivals.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given time interval.
If the mean number of arrivals is 10
This means that 
(a) that there will be exactly 15 arrivals?
This is P(X = 15). So


3.47% probability that there will be exactly 15 arrivals.
(b) no more than 10 arrivals?
This is 














58.31% probability that there are no more than 10 arrivals.
It is a 125% increase from 20 to 45