Math/ Statistics Flashcards
The complete collection of “all” individuals/items to be studied.
Population
A subcollection of members selected from the population.
Sample
A numerical measurement describing some characteristic of a population.
Parameter
A numerical measurement describing some characteristic of a sample
Statistic
Data consisting of numbers representing counts or measurements
Quantitative data
Quantitative data representing a finite or countable number
Discrete data
Quantitative data representing an infinite many possible values corresponding to some continuous scale that covers a range of values without gaps, interruptions or jumps
Continuous data
Data that consists of names or pavers or numbers that do not represent a count or measurement
Qualitative data
A sample of n subjects selected in such a way that every possible sample of size n has the same chance of being chosen
Simple Random Sample (SRS)
A sample in which the researcher selects some starting point and then selects every kth element in the population
Systematic sample
A sample in which the researcher subdivides the population into at least two different groups and draws a sample from each group
Stratified sample
A sample in which the researcher first divides the population into sections, and then randomly selects all members from some of those clusters.
Cluster Sample
A sample in which the researcher simply uses results that are very easy to get. This is not a valid sampling method and will likely result in biased data
Convenience sample
If the result of the sample are not representative of the population
Bias
The technique used to obtain the individuals to be in the sample tends to favor one part of the population over another
Sampling bias
When individuals selected to be in the sample who do not respond to a survey have different opinions from those who do
Nonresponse bias
When answers on a survey do not reflect the true feelings of the respondent.
Response bias
The idea that the sample must contain the characteristics of the population. One of the main concerns in the field of statistics is how accurately a statistic estimates a parameter
Representative sample
Part of the whole/ total
Proportion
The measure of center is a value at the center (or middle) of a data set of numbers.
Center of data
The average of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set
Mean
The middle value when a data set is ordered from leaf to greatest. When two values are in the middle, the _______ is the average of the two values.
Median
The number that occurs most often in a data set
Mode
A point that is not consistent with the bulk of the data from that group. These values can occur by chance, because of error in measurement, during data entry, or sampling errors.
Outlier
A value in a set of data such that k percent of the observations are less than or equal to the value. Decorated Pk
Percentiles
Divides the data set into fourths. The 25th, 50th and 75th percentiles
Quartiles
The highest frequency occurs in the middle and frequencies tail off to the left and the right of the middle
Bell-shaped Distribution (Normal)
The tail extends to the right of the peak longer than to the left. There are extreme values (outliers) to the right
Right-Skewed (positively skewed)
The tail extends to the left of the peak longer than to the right. There are extreme values (outliers) to the left.
Left-skewed (negatively skewed)
The degree to which the data are spread out.
Variation
The difference between the maximum data value and the minimum data value.
Range
A measure of how much data values deviate from the mean. It is the distance a data value is from the mean (center)
Standard deviation
Deviation about the mean - it is the square of the standard deviation.
Variance
The set of all possible outcomes of an experiment
Sample space
A long-term relative frequency of an outcome whose value is between zero and one, inclusive
Probability
When each outcome of an experiment occurs with equal probability.
Equally Likely
% that it is not going to happen
Complement
The probability that event A will occur given that event B has already occurred.
Conditional probability
Knowledge that one occurred does not affect the chance the other occurs.
Two events are independent
Members of the population are replaced after being selected and that each member can be chosen more than once.
Sampling with replacement (independent)
Members of the population are not replaced after being selected and that each member cannot be chosen more than once.
Sampling without replacement (dependent)
Events cannot occur at the same time, meaning that they share no common outcomes.
Mutually exclusive
The number of standard deviations that a data value x is above or below the mean.
Z-score (standardized score)
