Test 2- Chapter 3 and 4 Flashcards
Relative Frequency
Proportion/Percentage of the data values that fall in that category
= frequency in category
———————————-
total frequency
Cumulative Frequency
Number of data values in that category and all preceding categories
Bar Graph - Qualitative or Quantitative
Qualitative
Pareto Chart
Bar graph that is arranged in frequency order
Pie Chart -Qualitative or Quantitative
Qualitative
Histogram
Graph in which the bars have a natural order and the bar widths have specific meaning
Stem-and-Leaf plot (Stemplot)
Looks somewhat like a histogram turned sideways
Instead of bars is a listing of data for each category
Histogram- Qualitative or Quantitative
Quantitative
Line charts
Series of dots connected by lines
Line charts- Qualitative or Quantitative
Quantitative
Mean
sum of values/total number of values
Median
Middle value
Mode
Most common value(s)
Outliers
Value that is much higher or lower than almost all others
Affects mean
Weighted mean
Accounts for variations in the relative importance of data values
Each data value is assigned a weight
weighted mean= sum of (each data value x its weight)/sum of all weight
Ex.: (75x20)+(80x40)+(85x40)
————————————— =
20+40+60
81
——- = 81%
100
Number of modes
1- Unimodal distribution
2- Bimodal distribution
3- Trimodal distribution
Skewness
outliers in beginning/low outliers= left-skewed
outliers at end/high outliers= right-skewed
mode/median/mode all equal= symmetric
Variation
Go high in small space= low variation
Not to high/low over mid space= moderate variation
Low over long space= High variation
Range
Difference btw highest and lowest data values
= Max-Min
Quartiles
Lower Quartile/Q1= 25th
Median/Q2= 50th
Upper Quartile/Q3= 75th
5-Number Summary
lowest value
lower quartile
median
upper quartile
highest value
Percentiles
= number of values less than this data value
—————————————— x100
total number of values in data set
Standard Deviation
total number of data values - 1
then have to square root
deviation from mean= data value-mean
