stats unit 1

data acquisition considerations ; 3 of them

- time requirment - cost of acquistion - data errors

variable example

4 id, name, student, major

observation example

4 time 19

statistics refers to the ___ and ___ of collecting, intrepreting data

arts;science

A student counted the number of people who crossed an intersection in a one-hour period. She found that 23 people crossed the road during the one-hour period. She is interested in the number of people who would typically cross this intersection in a 12-hour day. Which of the following statements is true? a. The population is the 12-hour day. b. The sample consists of the 23 people who were observed crossing the road in the one-hour period. c. The population consists of the 23 people who crossed the road in the 12-hour period. d. The sample consists of all the people who cross the road in a 12-hour day.

b

The city would like to conduct a study of the opinions of its residents on an upcoming election. Since it would be too costly to call every person who is registered to vote in the city they decide to call every 15th person in the records database. Which of the following is correct? a. The data collected represent a census. b. The study is a sample survey. c. The study is an experimental study. d. The population average can be computed from the data collected.

b

Using data containing errors is always better than using no data at all. a. True b. False

b

Which of the following is a descriptive statistic? a. A bar chart b. All of these choices are correct. c. A histogram d. An average

b

Which of the following is an example of data typically available from internal company records? a. Federal Reserve Board b. Credit records c. Department of Commerce d. Census Bureau

b

data set that is collected at the same or approximately same point in time would be a. qualitative data. b. cross-sectional data. c. time series data. d. nominal data.

b

hospital has noted that on average there are 35 emergency room visits per month involving children. The average number of visits is an example of a. a sample. b. a descriptive statistic. c. a population. d. statistical inference.

b

Statistical studies in which researchers do not control variables of interest are a. invalid studies. b. experimental studies. c. observational studies. d. uncontrolled experimental studies.

c

sample survay

collecting data for a sample

time series data

data collected over several time periods

elements

entities in which data is collected

data

facts and figures collected, analyzed, and summerized for presentation

entitie example

number of students 19

qantitive are always _____

numeric

statistics

numerical facts such as averages, percentages etc

variables such as height ,weight, and time use the _____ ____

ratio scale

interval example

sat score 2200

sample

subset in a population

population

whole set of data

the scale must contain a ___ ____ that indicates that nothing exists for the variable at the 0 point

zero value

quantitive data

- how much or how many

categorial data

- lables and names used to identify an atribute of each element - often refered to as qualitative data - use either nominal or ordinal scale of measurment - can be either numeric or nonmeric - appropriate statistical analysis are limited

ordinal

- order matters - not numeric

scales of measurment include

-nominal -ordinal - interval -ratio

In an experiment, the investigator modifies the environment and controls the process being observed. a. True b. False

a

In order to determine whether a restaurant should offer service on Sunday the manager asked 50 regular customers if they would dine at the restaurant on Sundays. She found that 30, or 60%, would like the restaurant to open on Sundays. The 50 customers are an example of a. a sample. b. a population. c. statistical inference. d. a mean.

a

The table is an example of a. cross-tabulation data. b. time series data. c. continuous data. d. interval data.

a

Which of the following can be used to monitor the output of a production process? a. Unemployment rate b. An audit c. Value of a stock d. A quality control chart

a

Which of the following variables is quantitative? a. Weight of a package b. Phone number c. All of these choices are correct. d. Zip code

a

Which scale of measurement can be used with quantitative data? a. Ratio b. Any of these choices can be used for quantitative data. c. Nominal d. Ordinal

a

interval data are _____ ______

always numeric

All the data collected for a particular study are referred to as the a. populations. b. data set. c. samples. d. elements.

b

Which of the following areas of business and economics often uses statistical information to guide their investment recommendations? a. Production b. Marketing c. Accounting d. Finance

b

Which of the following is an example of an observational study? a. The temperature is measured each day for 30 days. b. All of these choices are examples of observational studies. c. Customer response to quality of service at a retail store is recorded for 200 customers. d. Students are asked what their favorite subject is in school.

b

Which of the following professionals frequently use statistical techniques to provide forecasts about the future of the economy? a. Financial Analysts b. Economists c. Accountants d. Managers

b

in a sample of 200 people who own a house, 180, or 90%, also own two or more vehicles. The 90% is an example of a. a sample. b. a descriptive statistic. c. a population. d. statistical inference.

b

Which of the following describes a population? a. A planned activity whose results yield a set of data. b. The complete collection of individuals or objects that are of interest. c. A sample of the individuals or objects that are of interest. d. A characteristic of an individual element.

c

a local grocery store recorded the amount spent for a sample of 50 customers who purchased groceries. Which of the following is not a true statement? a. The variable being studied is quantitative. b. The average amount spent is a descriptive statistic. c. This is an experimental study. d. This is an observational study.

c

survey of 40 students at an elementary school found that the average number of tardy days per semester was 15. The 15 is an example of a. a descriptive statistic. b. qualitative data. c. both choices "quantitative data" and "a descriptive statistic" are correct. d. quantitative data.

c

variable

characteristic of interest for the element A variable is any characteristics, number, or quantity that can be measured or counted.

census

collecting data for the entire population

A grocery store manager recorded the purchase amount of a sample of 75 customers who purchased groceries at their store. What data are being collected in this study? a. The number of customers who enter the store b. The type of merchandise they bought c. The age of the customer d. How much money they spent

d

Local residents were surveyed for their satisfaction with the local government. The responses were recorded as follows: 0-not satisfied, 1-somewhat dissatisfied, 2-satisfied, 3-very satisfied. The variable recorded is an example of what type of variable? a. a quantitative variable. b. a variable measured on the interval scale. c. a variable measured on the ratio scale. d. a variable measured on the ordinal scale.

d

Statistical inference a. is the same as descriptive statistics. b. refers to the process of drawing inferences about the sample based on the characteristics of the population. c. is the same as a census. d. is the process of drawing inferences about the population based on the information taken from the sample.

d

Statistical studies in which researchers control variables of interest are a. non experimental studies. b. observational studies. c. controlled observational studies. d. experimental studies

d

What does the term "statistics" refer to? a. Statistics refers only to the calculation of numbers, such as a mean. b. Statistics are used only in sports to calculate "stats" for teams and players such as average rushing yards. c. Statistics are rarely useful and informative. d. Statistics is the art and science of collecting, analyzing, presenting and interpreting data.

d

Where can you find statistics being reported? a. In a magazine b. In investment analyses c. On the radio d. All of these choices

d

Which of the following attributes is qualitative? a. The square footage of a house b. The number of movies seen by an individual in one year c. The number of boys in a class d. A person's favorite food

d

Which of the following describes a variable measured on an ordinal scale? a. It is a quantitative variable b. Arithmetic operations are meaningful c. The ratio of two values is meaningful d. Order can be assigned to the categories

d

Which of the following should be considered when acquiring data for a study? a. Time to collect data b. Cost to collect data c. The possibility of data acquisition errors d. All of these choices

d

sample of 100 individuals in a town was asked how much they paid in property tax per year. On the basis of this information, the reporter states that the average property tax bill of all residents of the town is $1500. This is an example of a. descriptive statistics. b. an experiment. c. a census. d. statistical inference.

d

nominal

data are labels and names used to identify an attribute of an element

all the data in a particular study are referred to as ____ ____

data sets

descriptive statistics

data summerised that could be graphical, tabular, or numerical

the scale indicates the ____ _______ and ____ ______ are the most appropriate

data summerization; statistical analyses

cross section data

data that is collected approximently in same point of time

ordinal example

freshman, sophmore, junior, senior

time series data example

graph in years

statistical inference

guessing - using data to make estimates and test hypothesis

the scale determines the amount of _____ contained in the data

information

data sources can be ______ or ______

internal; external

discrete

measuring how many

continous

measuring how much

numerical statistic

most common - mean and average

the total number of data values in a complete data set is the number of elements ____ by the number of variables

mutiplied

a _____ __ or _____ ___ maybe used

nonumeric label; numeric code

observational study

observe what is happening in a particular situatoin, recording data

observation

set of measurments obtained for a particular element

nominal example

students at university are classified by the school in which they are enrolled using a nonumeric label such as buisness, humanaties

ratio

the data have all the properties of interval data and the ratio of 2 values is meaningful

interval

the data have the properties of ordinal data and the interval between observation is expressed in terms of a fixed unit of measure

experimental data

variable of interst is first identified. than one or more other variables are controlled so the data can be obtained