The marketing club at school is opening a student store. They randomly survey 50 students about how much money they spend on lunch each day. What is the expected value for a student to spend on lunch each day?

Student Lunch Survey

\begin{tabular}{|c|c|}
\hline
\begin{tabular}{c}
Number of \\
Students
\end{tabular} & \begin{tabular}{c}
Dollars Spent on \\
Lunch Each Day
\end{tabular} \\
\hline
2 & [tex]$\$[/tex] 10[tex]$ \\
\hline
1 & $[/tex]\[tex]$ 8$[/tex] \\
\hline
12 & [tex]$\$[/tex] 6[tex]$ \\
\hline
23 & $[/tex]\[tex]$ 5$[/tex] \\
\hline
8 & [tex]$\$[/tex] 4[tex]$ \\
\hline
4 & $[/tex]\[tex]$ 3$[/tex] \\
\hline
\end{tabular}

A. [tex]$\$[/tex] 2.59[tex]$

B. $[/tex]\[tex]$ 5.11$[/tex]

C. [tex]$\$[/tex] 5.18[tex]$

D. $[/tex]\[tex]$ 9.07$[/tex]



Answer :

To find the expected value for a student to spend on lunch each day, follow these steps:

1. Understand the Data:
We have a survey that tells us how much money different numbers of students spend on lunch each day.

[tex]\[ \begin{array}{|c|c|} \hline \text{Number of Students} & \text{Dollars Spent on Lunch Each Day} \\ \hline 2 & \$10 \\ \hline 1 & \$8 \\ \hline 12 & \$6 \\ \hline 23 & \$5 \\ \hline 8 & \$4 \\ \hline 4 & \$3 \\ \hline \end{array} \][/tex]

2. Total Number of Students (N):
Add the number of students surveyed.

[tex]\[ N = 2 + 1 + 12 + 23 + 8 + 4 = 50 \][/tex]

3. Calculate the Weighted Sum of Money Spent:
Multiply the number of students by the dollars they spent and then sum these products.

[tex]\[ \text{Weighted Sum} = (2 \times 10) + (1 \times 8) + (12 \times 6) + (23 \times 5) + (8 \times 4) + (4 \times 3) \][/tex]

4. Perform the Multiplications:

[tex]\[ \text{Weighted Sum} = 20 + 8 + 72 + 115 + 32 + 12 = 259 \][/tex]

5. Expected Value Calculation:
The expected value [tex]\(E\)[/tex] is calculated by dividing the weighted sum of money spent by the total number of students.

[tex]\[ E = \frac{\text{Weighted Sum}}{N} = \frac{259}{50} = 5.18 \][/tex]

Therefore, the expected value for a student to spend on lunch each day is [tex]\(\$5.18\)[/tex].

So, the correct answer is:
[tex]\[ \$5.18 \][/tex]

Hence, the expected value for a student to spend on lunch each day is [tex]\(\$5.18\)[/tex].