Questions: Debbie has two stocks, X and Y. Consider the following events:
X= the event that the price of stock X has increased
Y= the event that the price of stock Y has increased
The event "the price of stock X has increased and the price of stock Y has not increased" may be written as
Multiple Choice
X' ∩ Y
X or Y'
X ∩ Y'
X or Y
Transcript text: Debbie has two stocks, $X$ and $Y$. Consider the following events:
$X=$ the event that the price of stock $X$ has increased
$Y=$ the event that the price of stock $Y$ has increased
The event "the price of stock $X$ has increased and the price of stock $Y$ has not increased" may be written as
Multiple Choice
$X^{\prime} \cap Y$
$X$ or $Y^{\prime}$
$X \cap Y^{\prime}$
$X$ or $Y$
Solution
Solution Steps
To determine the correct representation of the event "the price of stock $X$ has increased and the price of stock $Y$ has not increased," we need to use set notation for events. The event that stock $X$ has increased is denoted by $X$, and the event that stock $Y$ has not increased is denoted by $Y^{\prime}$. The conjunction "and" in set notation is represented by the intersection symbol $\cap$. Therefore, the correct representation is $X \cap Y^{\prime}$.
Step 1: Define the Events
Let \( X \) represent the event that the price of stock \( X \) has increased, and let \( Y \) represent the event that the price of stock \( Y \) has increased. The complement of \( Y \), denoted as \( Y' \), represents the event that the price of stock \( Y \) has not increased.
Step 2: Formulate the Desired Event
We are interested in the event where stock \( X \) has increased while stock \( Y \) has not increased. This can be expressed mathematically as the intersection of the events \( X \) and \( Y' \). Therefore, the event can be written as:
\[
X \cap Y'
\]
Step 3: Identify the Correct Option
Among the given multiple-choice options, the correct representation of the event "the price of stock \( X \) has increased and the price of stock \( Y \) has not increased" is \( X \cap Y' \).