Statistics HW 1

The participants in a research study are classified by marital status as single, married, or divorced/separated. This classification involves measurement on a nominal scale.

True

What additional information is obtained by measuring on an interval scale compared to a ordinal scale?

the size of the differences

Classifying people into two groups on the basis of gender is an example of measurement on an ordinal scale.

False

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.

What is the average miles per gallon (mpg) for all new hybrid small cars? Using Consumer Reports, a random sample of such vehicles gave an average of 35.7 mpg.

A.) Identify the variable. --miles per gallon B.) Is the variable quantitative or qualitative? --quantitative C.) What is the implied population? --all new hybrid small car

The archaeological site of Tara is more than 4000 years old. Tradition states that Tara was the seat of the high kings of Ireland. Because of it's archaeological importance, Tara has received extensive study (Reference: Tara: An Archaeological Survey by Conor Newman, Royal Irish Academy, Dublin). Suppose an archaeologist wants to estimate the density of ferromagnetic artifacts in the Tara region. For this purpose, a random sample of 55 plots, each of size 100 square meters, is used. The number of ferromagnetic artifacts for each plot is determined.

A.) Identify the variable. --number of ferromagnetic artifacts per 100 square meters B.) Is the variable quantitative or qualitative? --quantitative C.) What is the implied population? --the entire Tara region

Categorize these measurements associated with student life according to level: nominal, ordinal, interval, or ratio.

A.) Length of time to complete an exam. --ratio B.) Time of first class --Interval C.)Major field of study --nominal D.)Course evaluation scale: poor, acceptable, good --ordinal E.) Score on last exam --ratio F.) Age of student --ratio

Categorize these measurements associated with fishing according to level: nominal, ordinal, interval, or ratio.

A.) Species of fish caught: perch, bass, pike, trout --nominal B.) Cost of rod and reel --ratio C.) Time of return home --interval D.)Guidebook rating of fishing area: poor, fair, good --ordinal E.) Number of fish caught --ratio F.) Temperature of water --interval

In a friendly 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 being measured.

If there are three different samples of the same size from a set population, is it possible to get three different values for the same statistic?

Data from samples may vary from sample to sample, and so corresponding sample statistics may vary from sample to sample.

Using letter grades (A, B, C, D, and E) to classify student performance on an exam is an example of measurement on a(n) _______ scale of measurement.

Ordinal

Are data at the nominal level of measurement quantitative or qualitative?

Qualitative

After measuring a set of individuals, a researcher finds that Bob's score is three times greater than Jane's score. These measurements must come from a(n) ________ scale.

Ratio

Determining the number of students in each psychology course would be an example of measurement on a ratio scale. True or False

True

For a set population, does a parameter ever change?

never