Answer: Set of all real numbers
The domain is the set of all real numbers because we can plug in any x value we want to get some y value. There is no worry about dividing by zero. We don't have to worry about taking the square root of a negative number. There are no restrictions for x.
first, make an equation:

then, add twelve to both sides to remove it from the right:

then just divide by (-3) to get the value of x:

Answer:
The probability that a randomly selected call time will be less than 30 seconds is 0.7443.
Step-by-step explanation:
We are given that the caller times at a customer service center has an exponential distribution with an average of 22 seconds.
Let X = caller times at a customer service center
The probability distribution (pdf) of the exponential distribution is given by;

Here,
= exponential parameter
Now, the mean of the exponential distribution is given by;
Mean =
So,
⇒
SO, X ~ Exp(
)
To find the given probability we will use cumulative distribution function (cdf) of the exponential distribution, i.e;
; x > 0
Now, the probability that a randomly selected call time will be less than 30 seconds is given by = P(X < 30 seconds)
P(X < 30) =
= 1 - 0.2557
= 0.7443
Answer:
B. HL
Step-by-step explanation: