Business Statistics Exam 1
What is statistics? - correct answer-Science of gathering, presenting, analyzing, and
interpreting data
Uses math and probability
Convenient, not bias
Branch of Statistics: Descriptive - correct answer-Graphical or numerical summaries of data
Branch of Statistics: Inferential - correct answer-Making a decision based on data
Population - correct answer-The whole
Collection of all persons, objects, or items under study
Sample - correct answer-Gathering data on a subset of the population
Use info about the sample to infer about the population (statistical interference)
Parameter - correct answer-Descriptive measure of the POPULATION
Greek letters
Population parameter/average symbol
(population mean) - correct answer-μ
Population standard deviation - correct answer-σ
Population variance - correct answer-σˆ2
Statistic - correct answer-Descriptive measure of a SAMPLE
Roman letters
Sample mean - correct answer-x̅
Sample standard deviation - correct answer-s
Square root of the sample variance
Sample variance - correct answer-sˆ2
Average of the squared deviation from the arithmetic mean
Nominal - correct answer-Nonparametric (qualitative)
Classifying and counting
Values "name" the attribute
No ordering implied
Ex: gender, religion, ID# on a questionnaire, company tax ID
Ordinal - correct answer-Nonparametric (qualitative)
Ranking is possible for values of the variable
, Same as nominal, but in order (ranking)
Ex: ranking, rating, preference scales
Interval - correct answer-Parametric (quantitative)
Nominal and ordinal rule plus +,-,x,/ (means, standard deviation)
The distance between attributes does have meaning
Numerical data
Difference between numbers, location of origin
Ex: temperature in F, trade balance in money
Ratio - correct answer-Parametric (quantitative)
Nominal, ordinal, and interval rules
There is always a reference point that is meaningful
(0 for rates or 1 for ratio)
Ex: height, weight, volume, profit and loss, revenues, # tickets sold, per capita income
Frequency distribution - correct answer-Summary of data presented in the form of class
intervals and frequencies
Vary in shape and design
Constructed according to individual researchers preference
Steps in frequency distribution - correct answer-1: Determine range of it
2: Determine number of classes (5-15)
3: Determine width of class interval (width can be calculated by dividing range by # of
classes)
Midpoint - correct answer-Number in the middle of each interval
Ex: interval is 1-under3, midpoint is 2
Relative frequency calculation - correct answer-Frequency# / total frequencies
Cumulative frequency calculation - correct answer-First cumulative frequency will equal the
regular frequency number
Cumulative frequency before + new frequency
Ex: Freq: first = 4, second = 12, cumulative freq = 4+12=16
Histogram - correct answer-Vertical bar chart of frequencies
All of the bars are side by side (touching)
Bigger picture
Frequency polygon - correct answer-Line graph of frequencies
Mimic the shape of a histogram
X-axis = class midpoints
Ogive - correct answer-Line graph of CUMULATIVE frequencies
X-axis = class endpoints
Dot plots - correct answer-Plot of individual observations
What is statistics? - correct answer-Science of gathering, presenting, analyzing, and
interpreting data
Uses math and probability
Convenient, not bias
Branch of Statistics: Descriptive - correct answer-Graphical or numerical summaries of data
Branch of Statistics: Inferential - correct answer-Making a decision based on data
Population - correct answer-The whole
Collection of all persons, objects, or items under study
Sample - correct answer-Gathering data on a subset of the population
Use info about the sample to infer about the population (statistical interference)
Parameter - correct answer-Descriptive measure of the POPULATION
Greek letters
Population parameter/average symbol
(population mean) - correct answer-μ
Population standard deviation - correct answer-σ
Population variance - correct answer-σˆ2
Statistic - correct answer-Descriptive measure of a SAMPLE
Roman letters
Sample mean - correct answer-x̅
Sample standard deviation - correct answer-s
Square root of the sample variance
Sample variance - correct answer-sˆ2
Average of the squared deviation from the arithmetic mean
Nominal - correct answer-Nonparametric (qualitative)
Classifying and counting
Values "name" the attribute
No ordering implied
Ex: gender, religion, ID# on a questionnaire, company tax ID
Ordinal - correct answer-Nonparametric (qualitative)
Ranking is possible for values of the variable
, Same as nominal, but in order (ranking)
Ex: ranking, rating, preference scales
Interval - correct answer-Parametric (quantitative)
Nominal and ordinal rule plus +,-,x,/ (means, standard deviation)
The distance between attributes does have meaning
Numerical data
Difference between numbers, location of origin
Ex: temperature in F, trade balance in money
Ratio - correct answer-Parametric (quantitative)
Nominal, ordinal, and interval rules
There is always a reference point that is meaningful
(0 for rates or 1 for ratio)
Ex: height, weight, volume, profit and loss, revenues, # tickets sold, per capita income
Frequency distribution - correct answer-Summary of data presented in the form of class
intervals and frequencies
Vary in shape and design
Constructed according to individual researchers preference
Steps in frequency distribution - correct answer-1: Determine range of it
2: Determine number of classes (5-15)
3: Determine width of class interval (width can be calculated by dividing range by # of
classes)
Midpoint - correct answer-Number in the middle of each interval
Ex: interval is 1-under3, midpoint is 2
Relative frequency calculation - correct answer-Frequency# / total frequencies
Cumulative frequency calculation - correct answer-First cumulative frequency will equal the
regular frequency number
Cumulative frequency before + new frequency
Ex: Freq: first = 4, second = 12, cumulative freq = 4+12=16
Histogram - correct answer-Vertical bar chart of frequencies
All of the bars are side by side (touching)
Bigger picture
Frequency polygon - correct answer-Line graph of frequencies
Mimic the shape of a histogram
X-axis = class midpoints
Ogive - correct answer-Line graph of CUMULATIVE frequencies
X-axis = class endpoints
Dot plots - correct answer-Plot of individual observations
