Chapter 3.5, Problem 1E

a.

To determine

To find:The matrix organizing the data by listing the options in descending order and labeling the columns options, price, memory, color, and interface respectively.

Answer to Problem 1E

  $\left[\begin{array}{c}4\\ 3\\ 2\\ 1\end{array}\begin{array}{c}289\\ 315\\ 399\\ 420\end{array}\begin{array}{c}128\\ 256\\ 512\\ 512\end{array}\begin{array}{c}18\\ 24\\ 24\\ 24\end{array}\begin{array}{c}\text{wi-fi}\\ \text{infrared}\\ \text{bluetooth}\\ \text{infrared}\end{array}\right]$

Explanation of Solution

Given information:

Julie is shopping for a new smartphone and discovers that many different options are available.

  

Calculation:

The number of options is 4, so there will be 4 rows.

The labels of the columns are options, price, memory, color, and interface, so there will be 5 columns.

Then, the matrix will be of dimension $4\times 5$ .

Thus, the matrix is,

  $\begin{array}{l}\begin{array}{ccccc}\text{options}& \text{price}& \text{memory}& \text{color}& \text{interface}\end{array}\\ \left[\begin{array}{c}4\\ 3\\ 2\\ 1\end{array}\begin{array}{c}289\\ 315\\ 399\\ 420\end{array}\begin{array}{c}128\\ 256\\ 512\\ 512\end{array}\begin{array}{c}18\\ 24\\ 24\\ 24\end{array}\begin{array}{c}\text{wi-fi}\\ \text{infrared}\\ \text{bluetooth}\\ \text{infrared}\end{array}\right]\end{array}$

b.

To determine

To find: The dimensions of the matrix. The value of $a_{23}$

Answer to Problem 1E

The dimensions are $4\times 5$ .

  $a_{23}=256$

Explanation of Solution

Given information:

Julie is shopping for a new smartphone and discovers that many different options are available.

  

Calculation:

There are four rows and five columns.

So the dimensions are $4\times 5$ .

The value of $a_{23}$ , which is in the second row and third column, is 256.