Statistics Quiz 1

Statistics

the science of collecting, organizing, summarizing, and analyzing information to draw conclusions or answer questions

population

the entire group of individuals to be studied

sample

a subset of the group of individuals that is being studied

parameter

a numerical summary of a population

statistic

a numerical study of a sample

individual

a person or object that is a member of the group being studied

descriptive statistics

organizing and summarizing data through tables, graphs, and numerical summaries.

inferential statistics

use methods that take result from a sample and extends them to the population, and measures the reliability of the result

discrete variable

Has either a finite number of possible values or countable number of possible values. The values of these variables typically result from counting.

data

information that describes the characteristics of an individual

continuous variable

Has an infinite number of possible values that are not countable. The values of these variables typically result from measurement.

qualitative variable

allow for classification of individuals based on some attribute or characteristic.

quantitive variable

provide numerical measures of individuals. the measurements can be added or subtracted, and provided meaningful results

variable

the characteristics of the individuals within the population

simple random sampling

a basic probability method where every person or item in a large group has an exact, equal, and independent chance of being chosen

stratified sampling

a probability sampling method where a population is divided into distinct, non-overlapping subgroups called strata based on shared characteristics, and then samples are drawn from each subgroup

Describe a circumstance in which stratified sampling would be an appropriate sampling method.

when your population splits into distinct, non-overlapping subgroups (strata) that affect your study variable

Why are convenience samples ill advised?

they select participants based on easy access rather than random chance, which creates severe bias and makes it impossible to accurately represent a wider population

A frequency distribution lists the _______ of occurrences of each category of data, while a relative frequency distribution lists the ______ of occurrences of each category of data.

number, proportion

In a relative frequency distribution, what should the relative frequencies add up to?

1

frequency distribution

a data table showing how many times values or ranges occur

relative frequency distribution

lists each category or data value along with its proportion or percentage of the total dataset.

“skewed left”?

the lower tail is on the left

all bars are nearly the same

uniform

inverted bell cruve

middle is the lowest

bell curve

middle is the highest

bimodal shape (multimodal)

two distinct peaks

formula for a dice percentage

frequency histogram

a visual bar graph of that same data where the bars touch each other

mean

add all numbers then divide by amount of numbers

median

middle number. If even add the two middle numbers and divide by 2

mode

the number that shows the most