The owner of a local movie theater keeps track of the number of tickets sold in each purchase and makes a probability distribution based on these records. Let [tex]$X$[/tex] represent the number of tickets bought in one purchase. The distribution for [tex]$X$[/tex] is given in the table.

\begin{tabular}{|c|c|c|c|c|c|}
\hline
Number of Tickets & 1 & 2 & 3 & 4 & 5 \\
\hline
Probability & 0.29 & 0.44 & 0.19 & 0.06 & 0.02 \\
\hline
\end{tabular}

What is the expected value of the distribution?

A. 2
B. 2.1
C. 2.5
D. 3



Answer :

To find the expected value of the distribution, we follow these steps:

1. Define the random variable and probabilities: Let [tex]\( X \)[/tex] represent the number of tickets bought in one purchase. We have the following probability distribution:
- Number of tickets, [tex]\( X \)[/tex]: 1, 2, 3, 4, 5
- Corresponding probabilities, [tex]\( P(X) \)[/tex]: 0.29, 0.44, 0.19, 0.06, 0.02

2. Calculate the expected value: The expected value [tex]\( E(X) \)[/tex] of a discrete random variable [tex]\( X \)[/tex] is calculated using the formula:
[tex]\[ E(X) = \sum_{i} (x_i \cdot P(x_i)) \][/tex]
where [tex]\( x_i \)[/tex] is the number of tickets and [tex]\( P(x_i) \)[/tex] is the probability of [tex]\( x_i \)[/tex].

3. Compute each term in the sum:
- For [tex]\( x_1 = 1 \)[/tex]:
[tex]\[ 1 \cdot 0.29 = 0.29 \][/tex]
- For [tex]\( x_2 = 2 \)[/tex]:
[tex]\[ 2 \cdot 0.44 = 0.88 \][/tex]
- For [tex]\( x_3 = 3 \)[/tex]:
[tex]\[ 3 \cdot 0.19 = 0.57 \][/tex]
- For [tex]\( x_4 = 4 \)[/tex]:
[tex]\[ 4 \cdot 0.06 = 0.24 \][/tex]
- For [tex]\( x_5 = 5 \)[/tex]:
[tex]\[ 5 \cdot 0.02 = 0.10 \][/tex]

4. Sum the results:
[tex]\[ 0.29 + 0.88 + 0.57 + 0.24 + 0.10 = 2.08 \][/tex]

Therefore, the expected value of the distribution [tex]\( E(X) \)[/tex] is:

[tex]\[ E(X) = 2.08 \][/tex]

So, the correct answer is 2.1 (rounded to the nearest tenth).