Home > Preview
The flashcards below were created by user
ctbty
on FreezingBlue Flashcards.

population (1.1)
the collection of all outcomes, responses, measurements, or counts that are of interest

sample (1.1)
subset, or part, of a population

In a recent survey, 1500 adults in the US were asked if they thought there was solid evidence of global warming. 855 of the adults said yes. Identify the population and the sample. Describe the sample data set. (1.1)
The population consists of the responses of all adults in the US, and the sample consists of the responses of the 1500 adults in the US in the survey. The sample is subset of the responses of all adults in the US. The sample data set consists of 855 yes's and 645 no's.

parameter (1.1)
a numerical description of a population characteristic

statistic (1.1)
a numerical description of a sample characteristic

A recent survey of 200 college career centers reported that the avg starting salary for petroleum engineering majors is $83,121. Decide whether the numerical value describes a population parameter or a sample statistic. Explain your reasoning. (1.1)
B/c the avg of $83,121 is based on a subset of the population, it is a sample statistic.

The 2182 students who accepted admission offers to Northwestern University in 2009 have an avg SAT score of 1442. Decide whether the numerical value describes a population parameter or a sample statistic. Explain your reasoning. (1.1)
B/c the SAT score of 1442 is based on all the students who accepted admission offers in 2009, it is a population parameter.

In a random check of a sample of retail stores, the FDA found that 34% of the stores were not storing fish at the proper temp. Decide whether the numerical value describes a population parameter or a sample statistic. Explain your reasoning. (1.1)
B/c the % of 34% is based on a subset of the population, it is a sample statistic.

descriptive statistics (1.1)
the branch of statistics that involves the organization, summarization, and display of data

inferential statistics (1.1)
the branch of statistics that involves using a sample to draw conclusions about a population; a basic tool in this study is probability

A large sample of men, aged 48, was studies for 18 years. For unmarried men, approx. 70% were alive at age 65. For married men, 90% were alive at age 65. Decide which part of the study represents the descriptive branch of statistics. What conclusions might be drawn from the study using inferential statistics? (1.1)
Descriptive statistics involves statements such as "For unmarried me, approx. 70% were alive at age 65" and "For married men, 90% were alive at 65." A possible inference drawn from the study is that being married is associated w/ a longer life for men.

In a sample of Wall Street analysis, the percentage who incorrectly forecasted hightech earnings in a recent yr was 44%. Decide which part of the study represents the descriptive branch of statistics. What conclusions might be drawn from the study using inferential statistics? (1.1)
The part of this study that represents the descriptive branch of statistics involves the statement "the percentage [of Wall Street analysis] who incorrectly forecasted hightech earnings in a recent yr was 44%." A possible inference drawn from the study is that the stock market is difficult to forecast, even for pros.

qualitative data (1.2)
consists of attributes, labels, or nonnumerical entries

quantitative data (1.2)
consists of numerical measurements or counts

**The suggested retail prices of several Ford vehicles are sown in the table. Which data are qualitative data and which are quantitative data? Explain your reasoning. (1.2)
Model  Suggested retail price
The info shown in the table can be

observational study
when a researcher observes and measures characteristics of interest of part of a population but does not change existing conditions

experiment
when a treatment is applied to part of a population and responses are observed

simulation
the use of mathematical or physical model to reproduce the conditions of a situation or process

survey
an investigation of 1 or more characteristics of a population

confounding variable
occurs when a experimenter can't tell the difference b/w the effects of diff factors on a variable

blinding
a technique where the subjects don't know whether they are receiving a treatment or a placebo

placebo effect
occurs when a subject reacts favorably to a placebo when in fact the subject has been given no medicated treatment at all

doubleblind experiment
where neither the experimenter nor the subjects know if the subjects are receiving a treatment or a placebo

randomization
a process of randomly assigning subjects to diff treatment groups

completely randomized design
where subjects are assigned to diff treatment groups thru random selection

blocks
groups of subjects w/ similar characteristics

randomized block design
when subjects w/ similar characteristics are divided into blocks, and then, w/in each block, subjects are randomly assigned to treatment groups

matchedpairs design
where subjects are paired up according to a similarity

sample size
the number of subjects

replication
the repetition of an experiment under the same or similar conditions

census
a count of measure of an entire population

sampling
a count or measure of part of a population

sampling error
the difference b/w the results of a sample and those of the population

random sample
a sample in which every member of the population has an equal chance of being selected

simple random sample
a sample in which every possible sample of the same size has the same chance of being selected

stratified sample
used when it is important for the sample to have members from each segment of the population

cluster sample
used when the population falls into naturally occurring subgroups, each having similar characteristics

systematic sample
a sample in which each member of the population is assigned a number

convenience sample
consists only of available members of the population

