Tom's Electronics offers four models of cell phones (A, B, C, and D). Yesterday they sold 21 cell phones.

(a) The models that were sold appear below. Complete the frequency distribution for the data.
[tex]\[
\begin{array}{|c|c|c|c|c|c|c|c|}
\hline \text{Model} & \text{B} & \text{D} & \text{D} & \text{A} & \text{C} & \text{B} & \text{C} \\
\hline \text{} & \text{A} & \text{B} & \text{D} & \text{B} & \text{D} & \text{D} & \text{B} \\
\hline \text{} & \text{C} & \text{D} & \text{C} & \text{B} & \text{B} & \text{A} & \text{A} \\
\hline
\end{array}
\][/tex]

\begin{tabular}{|c|c|}
\hline
Model & Frequency \\
\hline
A & [tex]$\square$[/tex] \\
\hline
B & [tex]$\square$[/tex] \\
\hline
C & [tex]$\square$[/tex] \\
\hline
D & [tex]$\square$[/tex] \\
\hline
\end{tabular}

(b) There are four major phone plans available for these cell phone models, but not every plan is available for every model. The table below shows the plans available for the cell phone models.
[tex]\[
\begin{array}{|c|c|}
\hline \text{Phone Plan} & \text{Model} \\
\hline \text{Horizon} & \text{C} \\
\hline \text{Clear1} & \text{B and D} \\
\hline \text{Max Data} & \text{A, B, and C} \\
\hline \text{City Fone} & \text{A and D} \\
\hline
\end{array}
\][/tex]

How many cell phones sold at Tom's Electronics yesterday can use the Clear1 plan?
[tex]$\square$[/tex] phones



Answer :

Let's break down the solution step by step:

### (a) Frequency Distribution

First, we need to complete the frequency distribution for the cell phone models sold yesterday. The list of models sold is:

B, D, D, A, C, B, C, A, B, D, B, D, D, B, C, D, C, B, B, A, A

We will count the occurrences of each model:

- Model A: Count the number of 'A's.
- There are 4 'A's (A appears four times).

- Model B: Count the number of 'B's.
- There are 7 'B's (B appears seven times).

- Model C: Count the number of 'C's.
- There are 4 'C's (C appears four times).

- Model D: Count the number of 'D's.
- There are 6 'D's (D appears six times).

Now, we can complete the frequency distribution table:

[tex]\[ \begin{tabular}{cr} Model & Frequency \\ \hline A & 4 \\ B & 7 \\ C & 4 \\ D & 6 \\ \end{tabular} \][/tex]

### (b) Number of Phones Supporting Clear1 Plan

The Clear1 plan is available for models B and D. To determine how many cell phones sold yesterday can use the Clear1 plan, we add the frequencies of models B and D:

- Frequency of model B: 7
- Frequency of model D: 6

Adding these counts together:

[tex]\[ 7 (model \ B) + 6 (model \ D) = 13 \][/tex]

So, 13 phones sold at Tom's Electronics yesterday can use the Clear1 plan.