Answer:
(a) The expected number of should a salesperson expect until she finds a customer that makes a purchase is 0.9231.
(b) The probability that a salesperson helps 3 customers until she finds the first person to make a purchase is 0.058.
Step-by-step explanation:
Let<em> </em>the random variable <em>X</em> be defined as the number of customers the salesperson assists before a customer makes a purchase.
The probability that a customer makes a purchase is, <em>p</em> = 0.52.
The random variable <em>X</em> follows a Geometric distribution since it describes the distribution of the number of trials before the first success.
The probability mass function of <em>X</em> is:

The expected value of a Geometric distribution is:

(a)
Compute the expected number of should a salesperson expect until she finds a customer that makes a purchase as follows:


This, the expected number of should a salesperson expect until she finds a customer that makes a purchase is 0.9231.
(b)
Compute the probability that a salesperson helps 3 customers until she finds the first person to make a purchase as follows:

Thus, the probability that a salesperson helps 3 customers until she finds the first person to make a purchase is 0.058.
There are 11 trains containing giraffes and 7 trains containing rabbits.
<h3>
Equation</h3>
An equation is an expression used to show the relationship between two or more numbers and variables.
Let x represent the number of train with giraffes and y represent the number of train with rabbits.
Hence:
25x = 40y
25x - 40y = 0 (1)
Also:
25x + 40y > 500 (2)
From both equations:
A possible solution is x = 11, y = 7
There are 11 trains containing giraffes and 7 trains containing rabbits.
Find out more on Equation at: brainly.com/question/22688504
I think the answer is B. Darnell does not know how many rides he has already used. He knows he has 12 bus rides left on the bus pass.
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Answer:
This is all the above
Step-by-step explanation:
all answers are true to this graph