Answer:
a) There is a 55% probability that a person who walks by the store will enter the store.
b) There is a 38% probability that a person who walks into the store will buy something.
c) There is a 21% probability that a person who walks by the store will come in and buy something.
d) There is a 62% probability that a person who comes into the store will buy nothing.
Step-by-step explanation:
This a probability problem.
The probability formula is given by:
![P = \frac{D}{T}](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BD%7D%7BT%7D)
In which P is the probability, D is the number of desired outcomes and T is the number of total outcomes.
The problem states that:
121 people walked by the store.
66 people came into the store.
25 bought something in the store.
(a) Estimate the probability that a person who walks by the store will enter the store.
121 people walked by the store, 66 of whom entered the store. So:
![D = 66, T = 121](https://tex.z-dn.net/?f=D%20%3D%2066%2C%20T%20%3D%20121)
![P = \frac{D}{T} = \frac{66}{121} = 0.55](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BD%7D%7BT%7D%20%3D%20%5Cfrac%7B66%7D%7B121%7D%20%3D%200.55)
There is a 55% probability that a person who walks by the store will enter the store.
(b) Estimate the probability that a person who walks into the store will buy something.
66 people walked into the store, 25 of whom bought something. So:
![D = 25, T = 66](https://tex.z-dn.net/?f=D%20%3D%2025%2C%20T%20%3D%2066)
![P = \frac{D}{T} = \frac{25}{66} = 0.38](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BD%7D%7BT%7D%20%3D%20%5Cfrac%7B25%7D%7B66%7D%20%3D%200.38)
There is a 38% probability that a person who walks into the store will buy something.
(c) Estimate the probability that a person who walks by the store will come in and buy something.
121 people walked by the store, 25 of whom entered the store. So:
![D = 25, T = 121](https://tex.z-dn.net/?f=D%20%3D%2025%2C%20T%20%3D%20121)
![P = \frac{D}{T} = \frac{25}{121} = 0.21](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BD%7D%7BT%7D%20%3D%20%5Cfrac%7B25%7D%7B121%7D%20%3D%200.21)
There is a 21% probability that a person who walks by the store will come in and buy something.
(d) Estimate the probability that a person who comes into the store will buy nothing.
Of the 66 people whom came into the store, 25 bought something. This means that 66-25 = 41 of them did not buy anything. So:
![D = 41, T = 66](https://tex.z-dn.net/?f=D%20%3D%2041%2C%20T%20%3D%2066)
![P = \frac{D}{T} = \frac{41}{66} = 0.62](https://tex.z-dn.net/?f=P%20%3D%20%5Cfrac%7BD%7D%7BT%7D%20%3D%20%5Cfrac%7B41%7D%7B66%7D%20%3D%200.62)
There is a 62% probability that a person who comes into the store will buy nothing.