Exam 1: The Where, why, and How of Data Collection

The editor of a local newspaper is interested in determining the percentage of subscribers who read the paper's editorials.The statistical technique that he would use is called estimation.

Sales data measured each week for the past twenty weeks are examples of time-series data.

When the California Highway Patrol states that a study of drivers on a rural highway shows that the average speed is between 62.5 mph and 64.5 mph,they are most likely basing this statement on:

Data collected on the Internet can generally be considered accurate since the data must go through a screening process before they can be placed on the Internet.

Statistics is a discipline that involves tools and techniques used to describe data and draw conclusions.

A variable that has all the properties of an interval variable,but also has a true zero,is a ratio level variable.

A light bulb manufacturer wants to advertise the average life of its light bulbs so it tests a subset of light bulbs.This is an example of inferential statistics.

Stratified random sampling is the same thing as simple random sampling.

In conducting a personal interview,what problem can result if the interviewer is allowed to arbitrarily decide who should be interviewed?

If a systematic random sample is to be selected of size 100 from a population with 5,000 items,the first item selected from the ordered population will be:

The Polson Pole and Fence Company recently did a quality check on the length of fence posts.To do this,each of the 400 posts in inventory was numbered.Numbers from 1 to 400 were placed in a bowl.Twenty numbers were selected from the bowl without looking.These 20 poles were the ones selected for the study.This type of sampling is called:

Open the data file on your CD-ROM called AirlinePassengers.Indicate the level of data measurement for each variable in the data set.

Weekly stock closing prices for IBM would be classified as which of the following?

The difference between interval data and ratio data is that interval data has a natural zero.

Some of the most common methods of collecting data include experiments,telephone surveys,mail questionnaires,and direct observations and personal interviews.

Experimental design is a plan for performing an experiment where the effects of one or more factors on the variable of interest are measured.

In an unstructured interview the questions are scripted.

In a survey,what is meant by demographic questions and why might we want to include demographic questions in survey?

The human resources department at a major high tech company plans to conduct an employee satisfaction study by sampling 100 employees from the 3,000 total employees.They plan to use systematic random sampling since the employee file is in alphabetic order.The first employee selected in the study should be:

A variable,i.e.,the length of time it takes for an employee to complete an assembly procedure at an automotive plant,is a ratio level variable.