Statistics Test 1; HW 2

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): A man is selected by a marketing company to participate in a paid focus group. The company says that the man was selected because everyone in five randomly selected towns was being selected

Cluster

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): A market researcher has randomly selected three businesses in a certain region. She is serving all the employees from each business

Cluster

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): to determine customer opinion of their service, Business depot randomly selects 40 stores during a certain week and service our customers present in the store

Cluster

____ Occurs when you are not able to distinguish among the effects of different factors

Confounding

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): And Internet site asks its members to call in their opinion regarding their web researching habits

Convenience

Observational study or experiment? : 50 patients with brain cancer are divided into 2 groups. 1 group receives an experimental drug to fight cancer, the other a placebo. After 2yrs, the spread of cancer is measured.

Experiment

Experiment or observational study? Problem? : A study involves 22,071 mail positions. Based on random selections, 11,037 of them were treated with aspirin and the other 11,034 we're given placebos. The study was stopped early because it became clear that I asked for and reduce the risk of myocardial infarctions by a substantial amount

Experiment, a play treatment to, results apply only to male physicians

Difference between single-blind and double-blinded experiment

Ina single-blind experiment, the subject does not know which treatment is received. In a double-blinded neither does the researcher

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data : monthly temoeratures; 64°F, 68°F, etc

Interval

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data : water temperature in degrees celsius

Interval, data can be irdered, differences can be found and are meaningful, and there is no natural starting zero pt

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data : eye colors

Nominal, data cannot be ordered

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data then explain whats wrong with the given calculation: in a survey, the hair colors of respondents are identified as 10 brown, 20 blonde, 30 black, 40 anything else. The avg (mean) is calculated for 778 respondents and the result is 22.3.

Nominal, such data are not counts or measurements of anything, sonit makes no sense to compute their avg

___ The process of observing and measuring specific characteristics

Observation

Observational study or experiment? : in a study of 350 boys with a particular disease, the subjects were monitored with an EEG while asleep.

Observational

Experiment or observational study? In a survey, 1465 Internet users chose to respond to this question posted on the newspapers trying to condition: "is news online as satisfying as print and TV news? "52% of the respondents said "yes. " This is an_____ cuz the researchers ____ the jndividuals. Problem?

Observational study, Do not attempt to modify, This is a convenience sample with voluntary response, which has a high chance of leading to bias

Experiment or observational study? Problem? : A sociologist has created a brief survey given to 2000 adults randomly selected from the US population. Here are her first two questions: one. Have you ever been a victim of a felony crime? Two. Have you ever been convicted of a felony?

Observational study, does not attempt to modify, Most likely not to answer the second question truthfully

Experiment or observational study? Problem? : A medical researcher tested for a difference in sister sister Alex blood pressure levels between male and female students or 12 years of age. She randomly selected for males and four females for her study

Observational study, does not attempt to modify, the sample is too small

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data :the rankings of songs in the top 10

Ordinal

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): A large company wants to administer a satisfaction survey to its current customers. Using the customer database, the company randomly selects 30 customers and ask them about their level of satisfaction with the company.

Random

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): Email experienced a tax audit. The tax department claimed that the man was audited because he was randomly selected from all taxpayers

Random

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): in a poll. Conducted by a certain research center, 1222 adults or called after their telephone numbers were randomly generated by a computer, and 64% were able to correctly identify the secretary of state

Random sampling

Blank is used one subjects are assigned to different groups through a process of random Selection

Randomization

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): To determine her stress level, Britney divides up her day into three parts: morning, afternoon, and evening. She then measures her stress level at three randomly selected times during each part of the day

Stratified

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Apple selects every turn iPod that comes off the assembly line starting with the eighth until she obtains a sample of 60 iPods

Systematic

Determined the type of smapling mehtod (random, systematic, convenience, stratified, or cluster sampling): a researcher selectes every 734th social security # and surverys the person.

Systematic sampling

Determine which 4 leveks of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data : brain volumes measures in cubic cm

The ratio level of measurement, data can be ordered, differences can be found and are meningful, and there is a natural starting zero point.