QU1 Chapter 1.1 homework questions

Question 1

Suppose that three different types of beverages are sold at a fast-food restaurant - soft drinks, tea, and coffee. Explain why they type of beverage sold is an example of a categorical variable

Answer 1

(a) The types of beverages sold yield categorical or “qualitative” responses.
(b) The types of beverages sold yield distinct categories in which no ordering is implied.

Question 2

Suppose that soft drinks are sold in 3 sizes in a fast-food restaurant - small, medium and large. explain why the size of the soft drink is a categorical variable

Answer 2

Three sizes of soft drink are classified into distinct categories—small, medium, and large—in
which order is implied.

Question 3

Suppose that we measure the time it takes to download an MP3 file form the internet. explain why the download time is a numerical variable.

Answer 3

The time it takes to download an MP3 file from the internet yields numerical or
“quantitative” responses.

Question 4

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

a. number of telephones per household

Answer 4

numerical, discrete

Question 5

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

type of telephone primarily used

Answer 5

categorical

Question 6

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine
whether the variable of interest is discrete or continuous.

Number of long-distance calls made per month

Answer 6

numerical, discrete

Question 7

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

length (in meteres) of longest long-distance all made per month

Answer 7

numerical, continuous

Question 8

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

monthly charge in dollars and cents for long-distance calls made

Answer 8

numerical, continuous

Question 9

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

colour of telephone primarily used

Answer 9

categorical

Question 10

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

g. ownership of a cellular phone

Answer 10

categorical

Question 11

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

h. number of local calls made per month

Answer 11

numerical, discrete

Question 12

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

i. length (in minutes) of longest local call per month

Answer 12

numerical, continuous

Question 13

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

j. whether three is a telephone line connected to a computer modeum in the household

Answer 13

categorical

Question 14

For each of the following random variables, determine whether the variable is categorical or numerical. if the variable is numerical, determine whether the variable of interest is discrete or continuous.

k. whether there is a fax machine in the household

Answer 14

categorical