QMS102 Cribsheet final
Statistics - Statistics is the science of collecting organizing, presenting, analyzing and interpreting data. It turns
Data into information through transformation.
Population ! - Everyone in group ! !
- µ is the mean !
- σ is the standard deviation
Sample!
- Some/Portion of group !
-x is the mean!!
-S is the standard deviation
Measurement Scales
Types of Data
Categorical/Qualitative
Categorical/Qualitative
Nominal!
-Data has category but no order
Data that can only be in categories
!
!
-Example - martial status
!
!
-Can only count # of values in category
Numerical/Quantitative
Ordinal!-Data has categories in order.
Data values that represent quantities
!
!
-Examples - Grade scale -A+, A, A-, B+
!
-Discrete - Numerical Values that come from
!
! counting, if you count anything it is
Numerical/Quantitative
!
!
discrete. Such as the number of books
Interval!
-Has units of measure (rare!)
!
! you have.
!
!
-0 is a value
!
-Continuous - Produce numerical data that
!
!
-Ex - calendar, temperature
!
! comes from measuring, anything not
Ratio! !
-Zero means nothing (highest scale level)
!
!
ʻperfectʼ such as time, length, volume
!
!
-Discrete -OR- Continuous
!
!
-it is called ratio because half of 10km
!
! is 5km, but half of 10*c isnʼt 5*c, there
!
! arenʼt ratios w/ dates or temps.
STEM
Stem & Leaf Display - Organizes data to show shape and the distribution
How to construct:
1. Sort data in ascending order (0-10) - use calculator
2. Seperate into stem and Leaf (Label stem: tens, thousands, hundreds)
3. Group # w/ the same stems (stems in order)
4. Give title to your data
Rules for Stems:
1. Must have 6-13 Stems
2. Consecutive or repeated #s - can be repeated only 2 or 5 times
3. Units must be indicated (thousands, hundreds)
4. At least 1 leaf w/ the first and last stem.
LEAF
-1
876543210
0
1234
Rules for Leafs:
1. Leaf must be next single digit after stem, if # is 1673
Data into information through transformation.
Population ! - Everyone in group ! !
- µ is the mean !
- σ is the standard deviation
Sample!
- Some/Portion of group !
-x is the mean!!
-S is the standard deviation
Measurement Scales
Types of Data
Categorical/Qualitative
Categorical/Qualitative
Nominal!
-Data has category but no order
Data that can only be in categories
!
!
-Example - martial status
!
!
-Can only count # of values in category
Numerical/Quantitative
Ordinal!-Data has categories in order.
Data values that represent quantities
!
!
-Examples - Grade scale -A+, A, A-, B+
!
-Discrete - Numerical Values that come from
!
! counting, if you count anything it is
Numerical/Quantitative
!
!
discrete. Such as the number of books
Interval!
-Has units of measure (rare!)
!
! you have.
!
!
-0 is a value
!
-Continuous - Produce numerical data that
!
!
-Ex - calendar, temperature
!
! comes from measuring, anything not
Ratio! !
-Zero means nothing (highest scale level)
!
!
ʻperfectʼ such as time, length, volume
!
!
-Discrete -OR- Continuous
!
!
-it is called ratio because half of 10km
!
! is 5km, but half of 10*c isnʼt 5*c, there
!
! arenʼt ratios w/ dates or temps.
STEM
Stem & Leaf Display - Organizes data to show shape and the distribution
How to construct:
1. Sort data in ascending order (0-10) - use calculator
2. Seperate into stem and Leaf (Label stem: tens, thousands, hundreds)
3. Group # w/ the same stems (stems in order)
4. Give title to your data
Rules for Stems:
1. Must have 6-13 Stems
2. Consecutive or repeated #s - can be repeated only 2 or 5 times
3. Units must be indicated (thousands, hundreds)
4. At least 1 leaf w/ the first and last stem.
LEAF
-1
876543210
0
1234
Rules for Leafs:
1. Leaf must be next single digit after stem, if # is 1673