Chapter 1, Getting Started Video Solutions, Understandable Statistics, Concepts and Methods

01:21

Problem 1

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

Harsh Gadhiya

Numerade Educator

01:26

Problem 2

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

Harsh Gadhiya

Numerade Educator

00:35

Problem 3

What is the difference between a parameter and a statistic?

Harsh Gadhiya

Numerade Educator

01:50

Problem 4

For a set population, does a parameter ever change? 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?

Harsh Gadhiya

Numerade Educator

01:47

Numbers are often assigned to data that are categorical in nature.
(a) Consider these number assignments for category items describing electronic ways of expressing personal opinions:
$1=$ Twitter; $2=\mathrm{e}-$ mail; $3=$ text message; $4=$ Facebook; $5=$ blog
Are these numerical assignments at the ordinal data level or higher? Explain.
(b) Consider these number assignments for category items describing usefulness of customer service:
$1=$ not helpful; $2=$ somewhat helpful; $3=$ very helpful; $4=$ extremely helpful Are these numerical assignments at the ordinal data level? Explain. What about at the interval level or higher? Explain.

Harsh Gadhiya

Numerade Educator

01:48

Problem 6

Interpretation Lucy conducted a survey asking some of her friends to specify their favorite type of TV entertainment from the following list of choices:
sitcom; reality; documentary; drama; cartoon; other
Do Lucy's observations apply to all adults? Explain. From the description of the survey group, can we draw any conclusions regarding age of participants, gender of participants, or education level of participants?

Harsh Gadhiya

Numerade Educator

01:43

Problem 7

A national survey asked 1261 U.S. adult fast-food customers which meal (breakfast, lunch, dinner, snack) they ordered.
(a) Identify the variable.
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?

Harsh Gadhiya

Numerade Educator

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Problem 8

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 $35.7 \mathrm{mpg.}$
(a) Identify the variable.
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?

James Kiss

Numerade Educator

01:22

Problem 9

Government agencies carefully monitor water quality and its effect on wetlands (Reference: Environmental Protection Agency Wetland Report EPA $832-\mathrm{R}-93-005$ ). Of particular concern is the concentration of nitrogen in water draining from fertilized lands. Too much nitrogen can kill fish and wildlife. Twenty-eight samples of water were taken at random from a lake. The nitrogen concentration (milligrams of nitrogen per liter of water) was determined for each sample.
(a) Identify the variable.
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?

Harsh Gadhiya

Numerade Educator

01:35

Problem 10

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 its 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.
(b) Is the variable quantitative or qualitative?
(c) What is the implied population?

Harsh Gadhiya

Numerade Educator

02:43

Problem 11

Categorize these measurements 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

Harsh Gadhiya

Numerade Educator

02:14

Problem 12

Categorize these measurements associated with a robotics company according to level: nominal, ordinal, interval, or ratio.
(a) Salesperson's performance: below average, average, above average
(b) Price of company's stock
(c) Names of new products
(d) Temperature $\left(^{\circ} \mathrm{F}\right)$ in CEO's private office
(e) Gross income for each of the past 5 years
(f) Color of product packaging

Harsh Gadhiya

Numerade Educator

01:51

Problem 13

Categorize these measurements associated with fishing according to level: nominal, ordinal, interval, or ratio.
(a) Species of fish caught: perch, bass, pike, trout
(b) cost of rod and reel
(c) Time of return home
(d) Guidebook rating of fishing area: poor, fair, good
(e) Number of fish caught
(f) Temperature of water

Harsh Gadhiya

Numerade Educator

01:53

Problem 14

Education: Teacher Evaluation 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.
$$\begin{array}{ccccc}1 & 2 & 3 & 4 & 5 \\\text { worst } & \text { below } & \text { average } & \text { above } & \text { best } \\& \text { average } & & \text { average }\end{array}$$

Harsh Gadhiya

Numerade Educator

01:43

Problem 15

You are interested in the weights of backpacks students carry to class and decide to conduct a study using the backpacks carried by 30 students.
(a) Give some instructions for weighing the backpacks. Include unit of measure, accuracy of measure, and type of scale.
(b) Do you think each student asked will allow you to weigh his or her backpack?
(c) Do you think telling students ahead of time that you are going to weigh their backpacks will make a difference in the weights?

Harsh Gadhiya

Numerade Educator

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