Question

the table shows the movement of walt disney stock for 30 randomly selected trading days. up means the stock price increased in value for the day. down means the stock price decreased in value for the day, and no change means the stock price closed at the same price it closed for the previous day. complete parts (a)-(e) below. down down down down up up down up down up down up down down up up up up down down down up down up no change up down down no change no change (a) construct a probability model for stock movement of walt disney stock. stock movement probability up down no change (round to the nearest thousandth as needed.)

Explanation:

Step1: Count occurrences

Count the number of "Up", "Down", and "No - Change" days. By counting in the data, we find the number of "Up" days $n_{up}=12$, the number of "Down" days $n_{down}=15$, and the number of "No Change" days $n_{no - change}=3$. The total number of days $n = 30$.

Step2: Calculate probabilities

The probability of an event $E$ is given by $P(E)=\frac{n(E)}{n(S)}$, where $n(E)$ is the number of elements in the event $E$ and $n(S)$ is the number of elements in the sample - space.
For "Up": $P(Up)=\frac{n_{up}}{n}=\frac{12}{30}=0.400$.
For "Down": $P(Down)=\frac{n_{down}}{n}=\frac{15}{30}=0.500$.
For "No Change": $P(No\ Change)=\frac{n_{no - change}}{n}=\frac{3}{30}=0.100$.

Answer:

Stock Movement	Probability
Down	0.500
No Change	0.100