A teacher asks her students to write down the number of hours studied, rounded to the nearest half hour. She compiles the results and develops the probability distribution below for a randomly selected student. What is the mean of the probability distribution?

[tex]\[
\begin{tabular}{|c|c|}
\hline
\multicolumn{2}{|c|}{Probability Distribution} \\
\hline
\begin{tabular}{c}
Hours \\
Studied: $X$
\end{tabular} & Probability: $P ( X )$ \\
\hline
0.5 & 0.07 \\
\hline
1 & 0.2 \\
\hline
1.5 & 0.46 \\
\hline
2 & 0.2 \\
\hline
2.5 & 0.07 \\
\hline
\end{tabular}
\][/tex]



Answer :

To find the mean of a probability distribution, we need to sum the products of each value and its associated probability. Let's walk through the process step by step:

1. List down the hours studied and their corresponding probabilities:

[tex]\[ \begin{array}{c|c} \text{Hours Studied} & \text{Probability} \\ \hline 0.5 & 0.07 \\ 1 & 0.20 \\ 1.5 & 0.46 \\ 2 & 0.20 \\ 2.5 & 0.07 \\ \end{array} \][/tex]

2. Multiply each hours studied value by its corresponding probability:

[tex]\[ \begin{align*} 0.5 \times 0.07 & = 0.035 \\ 1 \times 0.20 & = 0.20 \\ 1.5 \times 0.46 & = 0.69 \\ 2 \times 0.20 & = 0.40 \\ 2.5 \times 0.07 & = 0.175 \\ \end{align*} \][/tex]

3. Add all these products together to get the mean:

[tex]\[ \begin{align*} 0.035 + 0.20 + 0.69 + 0.40 + 0.175 & = 1.5 \end{align*} \][/tex]

4. Thus, the mean of the probability distribution is:

[tex]\[ \boxed{1.5} \][/tex]