Chapter 1 Homework

What is the average miles per gallon (mpg) for all new cars? Using Consumer Reports, a random sample of 35 new cars gave an average of 21.1 mpg. (a) Identify the variable (b) Is the variable quantitative or qualitative? (c) What is the implied population?

(a) miles per gallon (b) quantitative (c) all new cars

Categorize these measurement associated with student life according to level: nominal, ordinal, interval, or ratio. (a) Length of time to complete an exam (b) Time of first class (c) Major field of study (d) Course evaluation scale: poor, acceptable, good (e) Score on last exam (based on 100 possible points) (f) Age of student

(a) ratio (b) interval (c) nominal (d) ordinal (e) ratio (f) ratio

What is the difference between a parameter and a statistic?

A parameter is a numerical measurement describing data from a population. A statistic is a numerical measurement describing data from a sample.

In a statistical study, what is the difference between an individual and a variable?

An individual is a member of the population of interest. A variable is an aspect of an individual subject or object.

If you were going to apply statistical methods to analyze teacher evaluations, which question form, A or B, would be better? Form A: In your own words, tell how this teacher compares with other teachers you have had. Form B: Use the following scale to rank your teacher as compared with other teachers you have had.

Form B would be better because statistical methods can be applied to the ordinal data.