10.2 Flashcards
Numbers that give some indication of the overalll “Average” of some data… Examples: mean, median, mode
Measures of Central Tendency
a measure of a numerical data set summarizes all of its values with a singe number…
Measure of Center
a measure that describes how its values vary with a single number.
Measure of variation
In a list of numbers, the number that occurs most frequently …. Note: there can be more than one or none.
Mode
The middle of the data…
Median
The sum of a collection of data divided by the quantity of data given…
Mean
Statistics that give an indication of how the data is distributed are called…. Example: Range
Measures of Dispersion
The difference of the largest and smallest scores…
Range
One way to get a sense of how the data is distributed is to construct a…. Note: Data needed-lowest score, highest score, median, upper quartiles and lower quartiles
Box and Whisker Plot or Box Plot
Find the median, then find the median of the lower set of numbers and you have found….
The Lower Quartile
Find the median, then find the median of the upper set of numbers and you have found the…..
Uppe Quartile
The difference between the upper and lower quartiles….
Interquartile Range (IQR)
Any value of the data that lies more than 1.5 IQR its below the lower quartile or more than 1.5 IQR units above the upper quartile……
Outlier
Steps to finding an outlier….
- Find the InterQuartile Range (IQR) Q3-Q1 2. Calculate the InterQuartile Range Boundary; 1.5 (Q3-Q1) 3. Identify any outliers; a.) Lower Quartile Boundary: Q1 - IQR Boundary b.) Upper Quartile Boundary: Q3 + IQR Boundary 4. a.) Mark any data less than the lower quartile boundary with an asterisk to indicate it is an outlier. b.) Mark any data greater than the upper quartile boundary with an asterisk to indicate it is an outlier.
dividing data into 100 equal parts; dividing points…
Percentiles
The arithmetic average of the squared differences between each number and the mean of the collection of numbers…..
Variance
List the steps to finding the variance of a set of numbers…
- Find the mean
- for each number x, find the difference between the number and the mean, so x - mean.
- square all the differences in step 2, (x-mean)2
- Find the arithmetic average of all the squares in step 3. This average is the variance.
The square root of the variance….
Standard Deviation
True or False; The greater the standard deviation, the more the scores are spread out.
True! The greater the standard deviation, the more the scores are spread out.
Score minus the mean of all scores divided by the standard deviation (indicating how many standard deviations the number is away from the mean)….
z-score
The percentage of the total amount of data that the number represents…..
Example: in a collection of 100 numbers, if the number 14 appears 6 times this is 6%…….
Relative Frequency
A graph of data versus the relative frequency of each number in the data is called…..
Distribution
A special type of smooth, bell-shaped distribution with the mean, median and mode all being equal….
Norrmal Distribution
