Math 115 Exam 1

Chebyshev's Theorem

1-1/k^2 75% of data lie w/in 2 SD of mean 88.9% of the data lie w/in 2 SD of mean

Statistics is

Collection of methods for planning experiments, obtaining data, organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on data.

discrete data

Data that can only take certain values.

continuous data

Data that can take any value

systematic sampling

Every nth item in the target population is selected

Eye colors are an example of which type of data? discrete, continuous, neither

Eye colors are an example of which type of data?

interval level

Level of measurement which classifies data that can be ranked and differences are meaningful. However, there is no meaningful zero, so ratios are meaningless.

Midpoint=

Lower Limit + Upper Limit

Q1= Q2= Q3=

Median of lower half Median Median of upper half

Sample standard deviation symbol

S

confounding variable

a factor other than the factor being studied that might influence a study's results

population is

a group of individuals of a single species that live and interact in one area

a statistic is

a numerical measurement describing some characteristic of a sample

sample is

a subset of the population

Empirical Rule (68-95-99.7) Rule

about 68% of the terms are within one standard deviation of the mean about 95% are within two standard deviations about 99.7% are within three standard deviations

ordinal level

applies to data that can be arranged in order

all members of a few groups is ________ sampling

cluster

"A large real estate firm wants to know the average price per square foot for condominiums in Oxford, MS. Based on real estate records for all condominiums in the city, the firm determines that condominiums in the Oxford area sell for approximately $300 per square foot." Identify: population, characteristic, census? if not, what's the sample?, is $300 a parameter or a statistic?

condos in oxford price per sq ft yes a parameter

"The governor of a Midwestern state wants to know his approval rating following a recent scandal. Using a telephone poll of registered voters in his state, 742 constituents are surveyed. The researcher determined that 65% of the governor's constituents that were surveyed currently approve of the job he is doing in office." Identify: population, characteristic, census? if not, what is the sample?, is 65% a parameter or a statistic?

constituents in the state approval rating no, 742 constituents statistic

Widths of the doors in a restaurant are an example of which type of data?

continuous

Descriptive or inferential ? 82% of the employees from a small local company attended the annual company picnic.

descriptive

qualitative data

descriptive data

Classify the quantitative variables as either continuous or discrete. a) Number of students that received an A on the first statistics test. b) The time it takes students to complete a one hour exam. c) Prices of a particular calculator at various stores.

discrete continuous discrete

Descriptive or inferential ? Based on information from a recent survey, researchers estimate that the average American will spend $751 on gifts this Christmas.

inferential

Indicate the level of measurement for the data set described. High temperatures (in degrees Fahrenheit) across the country for one day in July

interval

Release years of a list of 100 of the greatest movies of all time

interval

Indicate the level of measurement for the data set described. Eye colors extracted from a collection of passport photos

nominal

quantitative data

numerical data

inferential statistics

numerical data that allow one to generalize- to infer from sample data the probability of something being true of a population

parameter is

numerical summary of a population

observational study

observes individuals and measures variables of interest but does not attempt to influence the responses

Classify the data by the level of measurement. a) Birth month b) Temperatures across the state c) Favorite pizza topping d) Height of students in a statistics class

ordinal interval nominal ratio

Indicate the level of measurement for the data set described. Political orientation as reported by students in a political science class (left, center, right)

ordinal (left center right makes it order)

nominal level

qualitative data consisting of labels or names with no order

Number of class meetings in a term at various schools

ratio

A variance of 36.1 is shown as

s^2= 36.1

descriptive statistics

statistics that summarize the data collected in a study

a few members from a group is _________ sampling

stratified

Sample variance symbol

s²

ratio level

the interval level with an inherent zero starting point. Differences and ratios are meaningful for this level of measurement.

experimental study

the researcher manipulates one of the variables and tries to determine how the manipulation influences other variables

A modified box plot is used when _____ and extends its whiskers to the smallest and largest outliers denoted with a ______

there is an outlier, point or asterisk

Population standard deviation symbol

σ

Population variance symbol

σ²