Answer:

Step-by-step explanation:
We are given that Ben has a cell phone plan that provides 200 free minutes each month for a flat rate of $39.
We are also told that For any minutes over 200, Ben is charged $0.35 per minute.
let x be the minutes used each month
So, if 
So, coat will be $39
If 
So, Ben is charged $0.35 per minute
So, when 
So, charge = 
So, the piecewise functions accurately represents charges based on Ben's cell phone :

Answer:
9:30 she finishes
Step-by-step explanation:
815 plus 75 is 890
there are 60 minutes in one hour
890-60 is 830
add 100 to represent another Hour
830 plus 100 is 930
9:30
therefore, it is 9:30
So with this, I will be using the substitution method. With the first equation, substitute (y+3) into the x variable and solve for y:

Next, now that we have the value of y, substitute it into either equation to solve for x:

<u>And this is how you get your final answer (5,2).</u>
Answer:
Therefore, the probability that at least half of them need to wait more than 10 minutes is <em>0.0031</em>.
Step-by-step explanation:
The formula for the probability of an exponential distribution is:
P(x < b) = 1 - e^(b/3)
Using the complement rule, we can determine the probability of a customer having to wait more than 10 minutes, by:
p = P(x > 10)
= 1 - P(x < 10)
= 1 - (1 - e^(-10/10) )
= e⁻¹
= 0.3679
The z-score is the difference in sample size and the population mean, divided by the standard deviation:
z = (p' - p) / √[p(1 - p) / n]
= (0.5 - 0.3679) / √[0.3679(1 - 0.3679) / 100)]
= 2.7393
Therefore, using the probability table, you find that the corresponding probability is:
P(p' ≥ 0.5) = P(z > 2.7393)
<em>P(p' ≥ 0.5) = 0.0031</em>
<em></em>
Therefore, the probability that at least half of them need to wait more than 10 minutes is <em>0.0031</em>.
The value of f(0) is -1
<h3>What is a function?</h3>
A function can be defined as an expression, law or rule that explains the relationship between two variables; a dependent and an independent variable.
Given the function;
f(x)= -x - 1
To determine f(0), we substitute the value of x as 0 in the function
So, we have;
f(0) = -(0) - 1
f(0) = -0 - 1
f(0) = -1
Thus, the value of f(0) is -1
Learn more about functions here:
brainly.com/question/17043948
#SPJ1